diff --git a/src/hooks/usePaginatedReportActions.ts b/src/hooks/usePaginatedReportActions.ts
index a106da2b992f..f6d603773228 100644
--- a/src/hooks/usePaginatedReportActions.ts
+++ b/src/hooks/usePaginatedReportActions.ts
@@ -71,7 +71,8 @@ function usePaginatedReportActions(reportID: string | undefined, reportActionID?
         }
 
         if (reportActionID) {
-            return reportActionID;
+            const isInThisReport = sortedAllReportActions?.some((action) => action.reportActionID === reportActionID) ?? false;
+            return isInThisReport ? reportActionID : undefined;
         }
 
         if (!shouldLinkToOldestUnreadReportAction) {
diff --git a/src/pages/inbox/LinkedActionNotFoundGuard.tsx b/src/pages/inbox/LinkedActionNotFoundGuard.tsx
index 0dac7e857f85..af4d4b199b3f 100644
--- a/src/pages/inbox/LinkedActionNotFoundGuard.tsx
+++ b/src/pages/inbox/LinkedActionNotFoundGuard.tsx
@@ -1,6 +1,7 @@
 import FullPageNotFoundView from '@components/BlockingViews/FullPageNotFoundView';
 
 import useCurrentUserPersonalDetails from '@hooks/useCurrentUserPersonalDetails';
+import useNetwork from '@hooks/useNetwork';
 import useOnyx from '@hooks/useOnyx';
 import useReportIsArchived from '@hooks/useReportIsArchived';
 import useResponsiveLayout from '@hooks/useResponsiveLayout';
@@ -9,7 +10,7 @@ import useThemeStyles from '@hooks/useThemeStyles';
 import getNonEmptyStringOnyxID from '@libs/getNonEmptyStringOnyxID';
 import Log from '@libs/Log';
 import Navigation from '@libs/Navigation/Navigation';
-import {isReportActionVisible, isWhisperAction} from '@libs/ReportActionsUtils';
+import {getOneTransactionThreadReportID, isReportActionVisible, isWhisperAction} from '@libs/ReportActionsUtils';
 import {canUserPerformWriteAction} from '@libs/ReportUtils';
 
 import ONYXKEYS from '@src/ONYXKEYS';
@@ -66,14 +67,24 @@ function LinkedActionNotFoundGate({reportActionIDFromRoute, children}: LinkedAct
     const styles = useThemeStyles();
     const {accountID: currentUserAccountID} = useCurrentUserPersonalDetails();
     const {shouldUseNarrowLayout} = useResponsiveLayout();
+    const {isOffline} = useNetwork();
 
     const [report] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT}${reportIDFromRoute}`);
+    const [chatReport] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT}${getNonEmptyStringOnyxID(report?.chatReportID)}`);
     const [isLoadingInitialReportActions = true] = useOnyx(`${ONYXKEYS.COLLECTION.RAM_ONLY_REPORT_LOADING_STATE}${reportIDFromRoute}`, {
         selector: isLoadingInitialReportActionsSelector,
     });
-    const [linkedAction] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${reportIDFromRoute}`, {
+    const [reportActions] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${reportIDFromRoute}`);
+    const [linkedActionInRoute] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${reportIDFromRoute}`, {
         selector: (actions: OnyxEntry<ReportActions>) => getReportActionByIDSelector(actions, reportActionIDFromRoute),
     });
+
+    const transactionThreadReportID = getOneTransactionThreadReportID(report, chatReport, reportActions ?? {}, isOffline);
+    const [linkedActionInTransactionThread] = useOnyx(`${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${getNonEmptyStringOnyxID(transactionThreadReportID)}`, {
+        selector: (actions: OnyxEntry<ReportActions>) => getReportActionByIDSelector(actions, reportActionIDFromRoute),
+    });
+
+    const linkedAction = linkedActionInRoute ?? linkedActionInTransactionThread;
     const [visibleReportActionsData] = useOnyx(ONYXKEYS.DERIVED.VISIBLE_REPORT_ACTIONS);
 
     const isReportArchived = useReportIsArchived(reportIDFromRoute);
diff --git a/src/pages/inbox/report/ContextMenu/ContextMenuActions.tsx b/src/pages/inbox/report/ContextMenu/ContextMenuActions.tsx
index a78ff43799c1..a549b9cbeb69 100644
--- a/src/pages/inbox/report/ContextMenu/ContextMenuActions.tsx
+++ b/src/pages/inbox/report/ContextMenu/ContextMenuActions.tsx
@@ -174,6 +174,7 @@ import {
     changeMoneyRequestHoldStatus,
     getChildReportNotificationPreference as getChildReportNotificationPreferenceReportUtils,
     getDeletedTransactionMessage,
+    getDisplayedReportID,
     getIOUReportActionDisplayMessage,
     getMovedActionMessage,
     getMovedTransactionMessage,
@@ -1371,10 +1372,11 @@ const ContextMenuActions: ContextMenuAction[] = [
             const isDynamicWorkflowRoutedAction = isActionOfType(reportAction, CONST.REPORT.ACTIONS.TYPE.DYNAMIC_EXTERNAL_WORKFLOW_ROUTED);
             return type === CONST.CONTEXT_MENU_TYPES.REPORT_ACTION && !isAttachmentTarget && !isMessageDeleted(reportAction) && !isDynamicWorkflowRoutedAction;
         },
-        onPress: (closePopover, {reportAction, originalReportID}) => {
+        onPress: (closePopover, {reportAction, originalReportID, isOffline}) => {
             getEnvironmentURL().then((environmentURL) => {
                 const reportActionID = reportAction?.reportActionID;
-                Clipboard.setString(`${environmentURL}/r/${originalReportID}/${reportActionID}`);
+                const reportID = originalReportID ? getDisplayedReportID(originalReportID, isOffline) : originalReportID;
+                Clipboard.setString(`${environmentURL}/r/${reportID}/${reportActionID}`);
             });
             hideContextMenu(true, ReportActionComposeFocusManager.focus);
         },
diff --git a/tests/unit/ContextMenuActionsCopyLinkTest.ts b/tests/unit/ContextMenuActionsCopyLinkTest.ts
new file mode 100644
index 000000000000..bc8a239c076b
--- /dev/null
+++ b/tests/unit/ContextMenuActionsCopyLinkTest.ts
@@ -0,0 +1,108 @@
+import Clipboard from '@libs/Clipboard';
+import type * as EnvironmentModule from '@libs/Environment/Environment';
+import {getDisplayedReportID} from '@libs/ReportUtils';
+// eslint-disable-next-line no-restricted-imports -- type-only namespace (erased at runtime) used solely for the requireActual generic; no restricted functions are actually imported
+import type * as ReportUtilsModule from '@libs/ReportUtils';
+
+import ContextMenuActions from '@pages/inbox/report/ContextMenu/ContextMenuActions';
+import type {ContextMenuActionPayload} from '@pages/inbox/report/ContextMenu/ContextMenuActions';
+
+import CONST from '@src/CONST';
+
+import createRandomReportAction from '../utils/collections/reportActions';
+
+// Verifies the "Copy link" context menu action (change A for issue #86919): for one-transaction
+// expense flows the copied link must use the DISPLAYED (parent expense) report ID rather than the
+// transaction thread's `originalReportID`, so the link opens the combined view where the parent
+// "Submitted" system message is present and the linked message can be scrolled to.
+
+jest.mock(
+    'expo-web-browser',
+    () => ({
+        openAuthSessionAsync: jest.fn(),
+    }),
+    {virtual: true},
+);
+
+jest.mock('@components/Reactions/MiniQuickEmojiReactions', () => 'MiniQuickEmojiReactions');
+jest.mock('@components/Reactions/QuickEmojiReactions', () => 'QuickEmojiReactions');
+
+jest.mock('@libs/Clipboard', () => ({
+    __esModule: true,
+    default: {
+        canSetHtml: jest.fn(),
+        setString: jest.fn(),
+        setHtml: jest.fn(),
+    },
+}));
+
+jest.mock('@libs/Environment/Environment', () => ({
+    __esModule: true,
+    ...jest.requireActual<typeof EnvironmentModule>('@libs/Environment/Environment'),
+    getEnvironmentURL: jest.fn(() => Promise.resolve('https://new.expensify.com')),
+}));
+
+jest.mock('@libs/ReportUtils', () => ({
+    __esModule: true,
+    ...jest.requireActual<typeof ReportUtilsModule>('@libs/ReportUtils'),
+    getDisplayedReportID: jest.fn(),
+}));
+
+const mockClipboard = jest.mocked(Clipboard);
+const mockGetDisplayedReportID = jest.mocked(getDisplayedReportID);
+
+// ContextMenuAction is a union; sentryLabel/onPress only exist on the icon variant, so narrow with `in`.
+const copyLinkAction = ContextMenuActions.find((action) => 'sentryLabel' in action && action.sentryLabel === CONST.SENTRY_LABEL.CONTEXT_MENU.COPY_LINK);
+
+// Flush the microtasks queued by getEnvironmentURL().then(...) inside the onPress handler.
+const flushPromises = () =>
+    new Promise((resolve) => {
+        process.nextTick(resolve);
+    });
+
+function createPayload(overrides: Partial<ContextMenuActionPayload>): ContextMenuActionPayload {
+    // The copy-link handler only reads reportAction, originalReportID, and isOffline; the rest of the
+    // (large) payload type is irrelevant to this action, so we assert the minimal shape it needs.
+    const payload = {
+        reportAction: {...createRandomReportAction(1), reportActionID: 'action-1'},
+        originalReportID: 'transaction-thread-1',
+        isOffline: false,
+        ...overrides,
+    };
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion -- test payload only needs the fields the copy-link handler reads
+    return payload as ContextMenuActionPayload;
+}
+
+describe('ContextMenuActions copy link', () => {
+    beforeEach(() => {
+        jest.clearAllMocks();
+    });
+
+    it('copies a link using the displayed (parent) report ID for one-transaction expense flows', async () => {
+        mockGetDisplayedReportID.mockReturnValue('parent-expense-1');
+
+        if (!copyLinkAction || !('onPress' in copyLinkAction)) {
+            throw new Error('Copy link context menu action was not found');
+        }
+
+        copyLinkAction.onPress(true, createPayload({originalReportID: 'transaction-thread-1', isOffline: false}));
+        await flushPromises();
+
+        // The displayed report ID is resolved from the original (transaction-thread) report ID and the offline flag.
+        expect(mockGetDisplayedReportID).toHaveBeenCalledWith('transaction-thread-1', false);
+        // The copied link points at the parent expense report, not the transaction thread.
+        expect(mockClipboard.setString).toHaveBeenCalledWith('https://new.expensify.com/r/parent-expense-1/action-1');
+    });
+
+    it('does not resolve a displayed report ID when there is no original report ID', async () => {
+        if (!copyLinkAction || !('onPress' in copyLinkAction)) {
+            throw new Error('Copy link context menu action was not found');
+        }
+
+        copyLinkAction.onPress(true, createPayload({originalReportID: undefined}));
+        await flushPromises();
+
+        expect(mockGetDisplayedReportID).not.toHaveBeenCalled();
+        expect(mockClipboard.setString).toHaveBeenCalledTimes(1);
+    });
+});
diff --git a/tests/unit/hooks/usePaginatedReportActions.test.ts b/tests/unit/hooks/usePaginatedReportActions.test.ts
new file mode 100644
index 000000000000..e382e40f6081
--- /dev/null
+++ b/tests/unit/hooks/usePaginatedReportActions.test.ts
@@ -0,0 +1,192 @@
+import {renderHook} from '@testing-library/react-native';
+
+import useOnyx from '@hooks/useOnyx';
+import usePaginatedReportActions from '@hooks/usePaginatedReportActions';
+import useReportIsArchived from '@hooks/useReportIsArchived';
+
+import CONST from '@src/CONST';
+import ONYXKEYS from '@src/ONYXKEYS';
+import type {Report, ReportAction} from '@src/types/onyx';
+import type Pages from '@src/types/onyx/Pages';
+
+import type {OnyxKey, UseOnyxResult} from 'react-native-onyx';
+
+import createRandomReportAction from '../../utils/collections/reportActions';
+
+// The behavior change under test lives in the `id` useMemo of usePaginatedReportActions:
+// when a `reportActionID` is provided but does NOT exist in this report's own actions
+// (e.g. a one-transaction expense link where the linked message lives in the merged-in
+// transaction thread), the hook must fall back to the newest window instead of anchoring
+// pagination to a missing action. Previously, getContinuousChain returned an empty array in
+// that case (see tests/unit/PaginationUtilsTest.ts "given an input ID of 8 or 13 ... empty
+// array"), which is what hid the parent-level "Submitted" system message.
+//
+// We deliberately use the REAL getContinuousChain (PaginationUtils is not mocked) so these
+// tests exercise the true integration of the change with pagination, and only mock the Onyx
+// subscriptions so we can control the report, its actions, and its pages.
+
+jest.mock('@hooks/useOnyx', () => ({
+    __esModule: true,
+    default: jest.fn(),
+}));
+
+jest.mock('@hooks/useReportIsArchived', () => ({
+    __esModule: true,
+    default: jest.fn(() => false),
+}));
+
+const mockUseOnyx = jest.mocked(useOnyx);
+
+const REPORT_ID = 'expense-report-1';
+const LINKED_ACTION_ID = 'action-in-this-report';
+const SIBLING_ACTION_ID = 'action-in-transaction-thread';
+
+// `{status: 'loaded'}` alone satisfies ResultMetadata (its sourceValue is optional). A single
+// broad UseOnyxResult type keeps each mocked subscription value assignable without casts.
+type MockOnyxResult = UseOnyxResult<Report | ReportAction[] | Pages>;
+
+function makeReport(overrides: Partial<Report> = {}): Report {
+    return {
+        reportID: REPORT_ID,
+        type: CONST.REPORT.TYPE.EXPENSE,
+        chatReportID: 'chat-report-1',
+        ...overrides,
+    } as Report;
+}
+
+/**
+ * Minimal display-sorted actions (newest first). Ordering only needs to be internally
+ * consistent — getContinuousChain indexes by reportActionID, and the "newest window"
+ * result for empty pages returns the whole array regardless of order.
+ */
+function makeActions(reportActionIds: string[]): ReportAction[] {
+    return reportActionIds.map((reportActionID, index) => ({
+        ...createRandomReportAction(index),
+        reportActionID,
+        created: `2024-01-01 10:0${reportActionIds.length - index}:00.000`,
+    }));
+}
+
+/**
+ * Wire the three Onyx subscriptions usePaginatedReportActions makes: the report, its
+ * (already display-sorted) actions, and its pages. The selector on the actions key is
+ * bypassed by the mock, so we pass pre-sorted actions directly.
+ */
+function wireOnyx({report, actions, pages}: {report: Report | undefined; actions: ReportAction[] | undefined; pages: Pages | undefined}): void {
+    mockUseOnyx.mockImplementation((key: OnyxKey): MockOnyxResult => {
+        if (key === `${ONYXKEYS.COLLECTION.REPORT}${REPORT_ID}`) {
+            return [report, {status: 'loaded'}];
+        }
+        if (key === `${ONYXKEYS.COLLECTION.REPORT_ACTIONS}${REPORT_ID}`) {
+            return [actions, {status: 'loaded'}];
+        }
+        if (key === `${ONYXKEYS.COLLECTION.REPORT_ACTIONS_PAGES}${REPORT_ID}`) {
+            return [pages, {status: 'loaded'}];
+        }
+        return [undefined, {status: 'loaded'}];
+    });
+}
+
+function actionIds(actions: ReportAction[] | undefined): string[] {
+    return (actions ?? []).map((action) => action.reportActionID);
+}
+
+describe('usePaginatedReportActions', () => {
+    beforeEach(() => {
+        mockUseOnyx.mockReset();
+        jest.mocked(useReportIsArchived).mockReturnValue(false);
+    });
+
+    describe('when the linked action exists in this report (no behavior change)', () => {
+        it('anchors to the linked action and returns the report actions with pages absent', () => {
+            const actions = makeActions(['c', 'b', LINKED_ACTION_ID]);
+            wireOnyx({report: makeReport(), actions, pages: []});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, LINKED_ACTION_ID));
+
+            // Non-empty result and the linked action is surfaced — identical to pre-change behavior.
+            expect(actionIds(result.current.reportActions)).toEqual(['c', 'b', LINKED_ACTION_ID]);
+            expect(result.current.linkedAction?.reportActionID).toBe(LINKED_ACTION_ID);
+        });
+
+        it('anchors to the linked action within its page when pages are present', () => {
+            const actions = makeActions(['e', 'd', 'c', 'b', 'a']);
+            const pages: Pages = [['e', 'd', 'c', 'b', 'a']];
+            wireOnyx({report: makeReport(), actions, pages});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, 'c'));
+
+            expect(result.current.reportActions.length).toBeGreaterThan(0);
+            expect(result.current.linkedAction?.reportActionID).toBe('c');
+        });
+    });
+
+    describe('when the linked action is NOT in this report (the fix)', () => {
+        it('falls back to the newest window instead of returning an empty list, with pages absent', () => {
+            const actions = makeActions(['c', 'b', 'a']);
+            wireOnyx({report: makeReport(), actions, pages: []});
+
+            // SIBLING_ACTION_ID lives in the transaction thread, not in this report's own actions.
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, SIBLING_ACTION_ID));
+
+            // Before the fix this was [] (getContinuousChain empty-array behavior); now it is the newest window.
+            expect(actionIds(result.current.reportActions)).toEqual(['c', 'b', 'a']);
+            // No linked action is surfaced from this report — the host screen merges the thread separately.
+            expect(result.current.linkedAction).toBeUndefined();
+        });
+
+        it('falls back to the newest page instead of returning an empty list, with pages present', () => {
+            const actions = makeActions(['e', 'd', 'c', 'b', 'a']);
+            const pages: Pages = [['e', 'd', 'c']];
+            wireOnyx({report: makeReport(), actions, pages});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, SIBLING_ACTION_ID));
+
+            expect(result.current.reportActions.length).toBeGreaterThan(0);
+            expect(result.current.linkedAction).toBeUndefined();
+        });
+    });
+
+    describe('unchanged paths', () => {
+        it('returns the newest window when no reportActionID is provided', () => {
+            const actions = makeActions(['c', 'b', 'a']);
+            wireOnyx({report: makeReport(), actions, pages: []});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID));
+
+            expect(actionIds(result.current.reportActions)).toEqual(['c', 'b', 'a']);
+            expect(result.current.linkedAction).toBeUndefined();
+        });
+
+        it('ignores the anchor and never surfaces a linked action when treatAsNoPaginationAnchor is set, even if the action exists', () => {
+            const actions = makeActions(['c', 'b', LINKED_ACTION_ID]);
+            wireOnyx({report: makeReport(), actions, pages: []});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, LINKED_ACTION_ID, {treatAsNoPaginationAnchor: true}));
+
+            expect(result.current.reportActions.length).toBeGreaterThan(0);
+            expect(result.current.linkedAction).toBeUndefined();
+        });
+
+        it('resolves the oldest-unread anchor when shouldLinkToOldestUnreadReportAction is set and no reportActionID is provided', () => {
+            // lastReadTime is older than "b"/"c" but newer than "a", so the oldest unread action is "b".
+            const actions = makeActions(['c', 'b', 'a']);
+            const report = makeReport({lastReadTime: '2024-01-01 10:01:30.000'});
+            wireOnyx({report, actions, pages: []});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, undefined, {shouldLinkToOldestUnreadReportAction: true}));
+
+            expect(result.current.reportActions.length).toBeGreaterThan(0);
+            expect(result.current.oldestUnreadReportAction?.reportActionID).toBe('b');
+        });
+
+        it('returns an empty list without crashing when the report has no actions', () => {
+            wireOnyx({report: makeReport(), actions: [], pages: []});
+
+            const {result} = renderHook(() => usePaginatedReportActions(REPORT_ID, SIBLING_ACTION_ID));
+
+            expect(result.current.reportActions).toEqual([]);
+            expect(result.current.linkedAction).toBeUndefined();
+        });
+    });
+});