GPU performance tuning of "HZB SetupMips" (As seen in GPU Visualizer)

I’m not sure what’s going on here, but I’m in 4.18 and I’m getting this exact issue. I’ve been working in this same project for easily over a month and not run into this. The rest of my scene renders in sub 4ms. 4.18 has not resolved this issue whatsoever. Pretty disappointing.