Half of screen becomes solid grey intermittently during delirium map

pc
ryzen 5800x
rtx 4090
windows 10

bug report number 1,765,156,123

maybe has something to do with lightning strike / delirium / harbinger or certain auras. My other build didn't have this problem. Don't know exactly what cause, but as you can see from screenshot, it's below the UI layer. This happened several times in the map but did not persist after i finished clearing all the monsters in the map. I have a video I could upload if that would be helpful... but I couldn't discern anything