[Bug]: Error keybindings already in use, even after disabling Firefox's default shortcuts

[Arcthuruss]

Pre-Submission Checklist

• [X] I have checked the existing/closed issues to ensure this issue has not already been reported.
• [X] I am using the latest supported version of the browser.
• [X] I have tried disabling all browser extensions/add-ons to rule out interference from these.
• [X] I have tried clearing the browser cache and cookies.
• [X] I have checked with a new profile and the issue still occurs.
• [X] I have provided detailed step-by-step instructions on how to reproduce the issue.
• [X] I have included relevant screenshots or console outputs.
• [X] I have checked that this problem is not occurring in the latest version of Firefox ESR.
• [X] This issue is specific to this browser and does not occur in other browsers.

Bug Summary

after disabling Firefox's shortcuts and restarting the browser, the shortcuts are disabled as expected and I can assign new shortcuts that work but if try to assign a shortcut that was used by Firefox, I get an error telling the shortcut is already in use

Reproduction Steps

1. go to settings and disable Mozilla Firefox's keyboard shortcut
2. restart the browser for the change to take effect
3. try assigning a shortcut previously used by Firefox

Expected Behavior

Shortcut is assigned to action

Actual Behavior

Shortcut is declared already in use and cannot be assigned

Screenshots

https://github.com/user-attachments/assets/8b281453-01d0-402c-8f23-6b190cbc7509

Browser Version

11.19.1

Operating System

Ubuntu

Additional Context

No response

[CutterKnife]

By the way, what shortcut did you try to enter?

[Arcthuruss]

I tried Ctrl+T and Ctrl+Maj+N

[sabo-t]

Same issue, dont have any keybindings set and also disabled firefox keybindings. None work: ctrl+w, ctrl+q, ctrl+v ...

[Some1Lambda]

Same problem here, even when default Firefox keybinds are disabled, it is impossible to reuse them in custom shortcuts.

[brtholomy]

same on 11.19.1, Arch Linux AUR