@utzer ArchLinux, and yes, I already tried that. But also it shouldn't cause such UI issues. I'm not even talking about it taking a second or two to search for stuff, or to load a folder or to scroll through one. I'm just talking about navigating the UI or being responsive at all.
Since the last one or two updates it also sometimes "detects" the cursor on a completely different location than it is. But if I leave the window and reenter it with it then it's fine again...