Comment # 8 on bug 107213 from Pau Ruiz Safont

Same issue here, with the same error on dmesg:

GPU: R9 380 connected over Displayport
Monitor: DELL U2515H
CPU: AMD Ryzen 7 1700
Motherboard: ASRock AB350 Gaming-ITX/ac

OpenGL Renderer: AMD Radeon R9 380 Series (TONGA DRM 3.26.0 4.18.5-1-MANJARO
LLVM 6.0.1)
OpenGL version: 4.5 Mesa 18.1.7

I'm using KDE Plasma 5.13.4