Pressing Ctrl+Shift+S causes error and document will silently fail to save afterwards

[Nosrick]

Describe the Bug

I am running latest (as of 12/12/24) version of the CODE docker image and a NextCloud 29.0.9snap1 instance on the same physical machine which is operating on Ubuntu 24.04.1 LTS, restricted to a LAN. It is using HTTP as it is not allowed to go beyond the LAN and I am still trying to figure out the HTTPS side of things.

When editing a document, if I press Ctrl+Shift+S (usually by accident when trying to press Ctrl+S) this will bring up the Save As prompt, alongside an error:
"Cannot save document, please check your permissions."

If I cancel this download and continue editing, the document will appear to be functioning normally. When I save, the changes indicator (little blue dot) will vanish, and when hovered over will say "saved 3s ago" or something to that effect.

However, if changes are made after hitting Ctrl+Shift+S and cancelling the download, then the document is closed, all changes made following that cancelled Save As will be lost permanently. No new versions of the file will be created. No changes are written to disk. I have lost hours of work to this, and I am unsure how to recover it, if it is even possible.

Steps to Reproduce

1. Open an established .docx file.
2. Press Ctrl+Shift+S
3. Close the Save As prompt
4. See error: "Cannot save document, please check your permissions."
5. Close the error
6. Make further changes to the document
7. Save the document with either Ctrl+S or the Save button
8. Close the document
9. Re-open the document
10. Observe lost changes

Expected Behavior

Worst case: a visual warning to the user that data loss will occur if they continue to make changes to the document.

Best case: there is no data loss. No error occurs and editing continues as normal.

Actual Behavior

After the error occurs, the document seems to operate normally. It tells me it has saved successfully X seconds ago. It allows me to make changes. There is no indication that anything is wrong at all. Nothing in the NextCloud logs. No changes are actually saved. No further versions of the file are created. When the document is closed, all progress since the Save As operation is lost.

Screenshots

No screenshots, but have attached the Docker log for the CODE container starting when the document is opened.

Desktop

• Collabora version: 24.04.10.2 a4b67a7
• NextCloud Snap 29.0.9snap1
• OS and version: Ubuntu 24.04.1 LTS
• Browser and version: Multiple browsers tested, all same behaviour

Additional Context

Environment is communicating using HTTP.

error.log