Which KDE version? If it is " Dragonized Gaming Edition" I wonder if it’s proton-ge-custom package is causing issues (unsupported AUR version of Proton GE that seems to be packaged differently). I’ve recently identified it was causing issues for Steam even if a game wasn’t using it. Issues like odd controller issues if the controller was plugged in prior to starting Steam; requiring the controller to be reconnected to use Steam Input (like this issue that @iBolski has been having:
Although I only have a Playstation 4 Controller to test with and I am having similar issues until I remove that proton-ge-custom package.
There might be a chance there are other weird issues this package is causing too considering you didn’t notice the issue on the other flavor of Garuda.
If you have that type of Proton GE package installed and want to see if removing it fixes your issues, make sure all games are swapped off from using that version of Proton in Steam beforehand (and maybe backup saves too just in case). Exit Steam, then you should be able to remove that package of Proton GE. (Not sure if a complete system restart is required considering how many libraries Steam pulls in, but if you still have issues after removing the package, I would restart)
If you still require Proton GE for games, the package protonup-qt is a great way to get them (the GUI for it seems pretty straight forward). It’s also in the chaotic-aur repo.