This was shared in another report about the black screen issue. I tried the first one shared by Calaart and it worked just fine. I haven’t had a problem since.
in the battle net launcher, click the blizzard logo in the top left, go to settings
game settings
go down to world of warcraft
check the box “additional command line arguments”
then in the text box that appears type “-d3d11” without the "
Alada shared this option. I haven’t had a chance to try it out because the first one fixed my issue but some people said the first fix didn’t work for them and this one did.
1.World of warcraft
2.retail
3.WTF
4.Config
5. Find the line that says SET gxApi “D3D12” and switch to “D3D11”