Weird scroll behavior in some apps in Fedora 34

I have a serious problem with my Fedora 34 installation. It seems to do certain random events. Few examples:

  • If I click on a tab in Chrome, it will scroll along the tabs (basically switching to the tab on the left, until I move mouse off the tab bar). Firefox doesn’t have that problem.
  • if I hold Ctrl Key with an active prompt in Terminator shell, it will keep enlarging the font (like Ctrl+mouse wheel). The default Terminal app doesn’t do that.
  • similarly, holding down Shift seems to scroll the terminal up (in Terminator)

Pressing Shift (in Terminator) also brings

It seems to be similar to this (Fedora 34 - All windows scroll sporadically by themselves - #4 by vvot), but changing mouse and keyboard did not help + they work on other computers around the house.

I believe this has started around when I upgraded from Fedora 33 to 34, no hardware changes aside from adding an additional SSD in the meantime.

Does anybody have similar experience? What could I look into, to try and find the problem?

Journalctl, dmesg don’t seem to see anything out of the ordinary (apart from the usual problems).