Comment # 1 on bug 1002642 from Max Staudt

I've seen this at some point on a system with a 3840x2160 screen, running the
xf86-video-ati DDX. Unfortunately I can't reproduce it on Tumbleweed right now.

Would you like to try the xf86-video-ati I'm preparing for Tumbleweed? There's
a Leap 42.1 build available:

https://build.opensuse.org/package/show/home:mstaudt:branches:X11:XOrg/xf86-video-ati