Try out the latest Taproom Linux build v3.0.2.
This automatically applies the GTK 3 flag and should fix the issue
We're currently investigating this issue right now, it appears to be because of an upstream Electron change where they integrated GTK 4.
After some testing we'll publish revised builds, likely just forcing on GTK 3 like this post suggests
https://www.electronjs.org/blog/electron-36-0#behavior-changed-gtk-4-is-the-defa...