I've had this issue plenty of times.
Premiere is ancient software that is poorly optimized for modern workflows. Even with 8GB of VRAM, your graphics card could run out of memory if you're dealing with 6 or 8K footage and/or color grading. The black screen happens when Mercury Playback runs out of memory. It's not programmed to warn you, it will just show a black screen and sometimes crash.
This happens on footage that is a bit more difficult to decode I guess because it's not only about the resolution, sometimes it happens because it's RED footage.
Obviusly software rendering is out of the question even on my 32 core Threadripper, so the only workaround I found is to create proxies like it's 1999.