Quick tip: Type @ and a modal will appear allowing you to select a user from a dropdown. This has the benefit of ensuring you don’t spell a user’s name incorrectly, and notifying them that they have been mentioned; without that, they may never know.
The only controller I use is a keyboard, unfortunately.
However, if any of those games (via Steam) are Windows based, then this recent note in Known Issues and Solutions may have some bearing on it; albeit not directly:
WINE with WoW64 is known to be not as performant as previous iterations using pure 32-bit. Perhaps it’s worth seeing what Valve might have to say about it.
Otherwise, I can only suggest searching forum topics in case anyone else has a similar issue, and wait for input from others (many gamers use Manjaro and might have encountered this already).
Regards.