Im happy to see that im not the only one with this issue. Thought its my GPU…
On topic, yes its tarted happening in 8.1.5 and now in 8.2, its happening every day so im forced to play in DX11. What actually happems, WoW is crashing and auto switching to DX11. Thats why the screen freezes.
Made a post with the error log/dxiag here: DX12 constantly crashing, game auto swtiches to DX11