I don’t think so, it’s been reported here by others with a 1080.
Here’s another thread on it: Black box textures/animations in some acts - #10 by LoFaT-1708
Here’s what I get in windowed mode, the black boxes turn into red boxes:
https://i.imgur.com/ZpTfBTG.png
https://i.imgur.com/06ANrJU.png
Then switching it back to fullscreen and it’s completely bugged out:
https://i.imgur.com/1O0xbib.png
https://i.imgur.com/NgXIB4L.png
Strangely… it has disappeared for now. After it fully bugged out in the above pics I restarted D2R and the settings say fullscreen but I can still see my windows bar at the bottom. So it LOOKS windowed but the settings say fullscreen, despite not being fullscreen. But the black boxes have disappeared for now. I suspect this is temporary and it will come back again, will have to wait and see