Thanks for the tips. I’ve tried all those previously except running the game drivers. I’ve stuck with studio drivers for the stability purposes. I did however find that I had an extra Niagara system that got missed when I was changing the simulation method to GPU. When I switched all the Niagara systems to GPU simulation the flashing went away immediately and has stayed away. So that’s what the black flashing was related to. Why? I have absolutely no idea. Maybe the Niagara systems using the CPU to calculate was conflicting with the GPU in some way? In any case, that’s how I solved it – turning all the Niagara systems to GPU simulation instead of CPU.