Create a new Firefox profile, set it as default, then restart Firefox and see if the problem still persists.

I am listening to music while reading this.

Just install WineHQ

Linux mint. It’s based on Ubuntu but they also snapped out the snaps.

Oh, I just misunderstood your post.

No. You can just do sudo apt install kde-minimal or sudo apt install kde-full. If you see a popup asking you to select SDDM or GDM, select GDM for GNOME to still have the screen lock function.

Then log out, click your user, click on the ⚙️ and select Plasma. Now just log in and you can do this again if you want to go back to GNOME.

There was that kind of bug in Linux and a person restarted it idk how much (iirc around 2k times) just to debug it.