Extreme lag in the Sump maps

I’m getting extreme lag on the Sump map. None of the others. It’s not flickering like it does at the Ziggurat, it’s slowing to the point that the map is unplayable.

I’m playing on Xbox series X on standard settings. I’ve enabled the Dynamic Culling, which helps a bit, but the maps are still horrifically slow. I’ve also turned Bloom down to 80.