It's not only WoW. After reboot i see garbage instead of sddm login screen.
Here is a photo https://ibb.co/fQ7dqQ

Radeon HD 7750

Device: AMD CAPE VERDE (DRM 2.50.0 / 4.12.3-gentoo, LLVM 4.0.1) (0x683f)
Version: 17.3.0
Accelerated: yes
Video memory: 1024MB
Unified memory: no