Cannot open saved drawio files

[headcase0570]

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Describe the bug
A clear and concise description of what the bug is.
I have made a diagram on my Macbook using the https://draw.io website. I saved the diagram manually to my device's Onedrive folder (not through the save to Onedrive option)
A day later I thought to check on the file using my Windows 11 PC, and the https://draw.io website, I opened the devices' folders, navigated to the diagram file but upon opening It I get an error:
No Diagram file (error on line 1 at column 1: Start tag expected, '<' not found)

To Reproduce

1. Steps to reproduce the behavior:
2. Go to https://draw.io on Macbook
3. Create a diagram and save it to device.
4. Move diagram to Onedrive folder
5. Go to https://draw.io on Windows machine
6. Open diagram from 'Device', nagivate to Onedrive folders.
7. Open saved diagram
8. Get error

Expected behavior
I expect diagrams made in the browser version of https://draw.io to work when opening them in another browser.

Screenshots
If applicable, add screenshots to help explain your problem.

draw.io version (In the Help->About menu of the draw.io editor):
v26.0.10

Desktop (please complete the following information):

• OS: Windows 11 pro, fully updated

• Browser Chrome

• Browser Version 132.0.6834.160 (latest)

• OS: MacOS

• macOS Sequoia 15.2

• Browser Chrome

• Browser Version 132.0.6834.112 (latest)

I tested the problem in incognito/private mode with all browser extensions switched off, write "yes" below:
yes

Additional context
Add any other context about the problem here.

[davidjgraph]

There's a known issue saving to onedrive synced folder, onedrive does something that other cloud drives don't and we can't find the problem.

Onedrive has file revision history, restore the previous version.

[headcase0570]

It takes an even stranger turn apparently. I've exported my diagram to .pdf on my laptop, moved the export to Onedrive and opened the .pdf on the PC, instant corruption!
The issue isn't limited to draw.io diagram files but also exported files.
I'm willing to share these files if it'll help with troubleshooting but I don't see an upload function in this post system