(In reply to Ernst Sjöstrand from comment #3)
> I happen to have 2 4K monitors and a Fury as well actually.
> 
> I actually couldn't run Wayland at all for some time, perhaps it was fixed
> by:
> mutter (3.22.2-3) unstable; urgency=medium
> 
>   [ Jeremy Bicha ]
>   * Add git_flush_all_swap_notifies_on_idle.patch:
>     - Add patch from 3.22 branch that fixes freezes with multiple monitors
>       on Wayland
> landing in my Ubuntu repos.
> 

That's also in Fedora as far as I can tell:
https://koji.fedoraproject.org/koji/buildinfo?buildID=823521

(In reply to Ernst Sjöstrand from comment #4)
> Does it work with an older mesa/llvm version for you?

Mesa 13 and LLVM 3.8 in stock Fedora doesn't help.