I... It seems to work now... I had the impression it was based on the keyboard layout that was used because it worked on another computer with a different physical layout. On my gaming desktop, with an AZERTY keyboard, I have two layouts set up: one for French and one for UK (other games that don't allow keyboard mapping required such a setting).
Any in case:
- Browser: Firefox v107 x64
- Device: er, a custom-built desktop (that I assembled 😊)
- OS: Windows 11