(In reply to John Smith from comment #22)
> (In reply to Johannes Hirte from comment #21)
> > Any possibility to test with 5.3 kernel? It seems it's fixed but not
> > backported.
> 
> If I'm understanding it correctly, backported means it already should be in
> 5.4, no?

You're right, I've read it wrong. 

>From the reports, it seems to be compositor related. For me, kwin with OpenGL
3.1 backend works fine. xfwm4 seems to trigger the bug, maybe other compositors
too.