I've seen this problem in the steam forum but it is still happening:

I start the game on Linux, it runs in window-mode. Resolution is not changeable at 1080p, not suitable for my 1440p screen. So I enable full screen-mode. When on my secondary 1080p monitor, it shifts the mouse cursor, making navigating through UI a hassle. On my main 1440p monitor, mouse clicks don't get recognized at all in full screen. This makes it unplayable.

I've never experienced this in any other game or when playing through Steam. How do I fix this? I really don't want to play in a tiny window because of something like this. Otherwise, I guess I need to get a refund.

People with similar problems:
https://steamcommunity.com/app/396750/discussions/1/4515505180230010296/
https://forums.funcom.com/t/mouse-pointer-wrong-position-in-fullscreen-when-taskbar-is-at-the-top/5829


I just found out that sound is also NOT working. Why is this marked as Linux compatible again??