Bug: Hover highlight disappears after ~1s and clicks on items stop registering (regression in 4.3.0) #19058

Description

On Files 4.3.0.0, hovering over an item causes the hover highlight to appear and then vanish after roughly one second, while the pointer is still resting on the item. Clicks made while this happens are frequently not registered — a second click is usually needed. The behaviour occurs across the app, not just in the Omnibar, and is not tied to a specific layout.

Regression is confirmed, the issue is not present in version 4.2.9.

Steps To Reproduce

1. Install Files 4.3.0.0 via choco install files
2. Open Files and navigate to any folder containing several files/folders.
3. Hover the mouse over a single item and hold the pointer still — do not move it.
4. Observe the item: the hover highlight appears, then fades/disappears after approximately one second, despite the pointer not moving.
5. While the highlight is gone, left-click the item. The click is frequently not registered — the item is not selected/opened, and a second click is normally required.
6. Repeat across different folders and layouts. The behaviour is not limited to the Omnibar and is not layout-specific.
7. Control: install 4.2.9 (choco install files --version=4.2.9) and repeat steps 2–5. The hover highlight holds and clicks register on the first attempt.

Files Version

4.3.0

Windows Version

10.0.26200

User ID

No response

Log File

debug.log