Very low poly.
I noticed you have streamed levels. Did you unload some, or all?
You must get a massively high fps on an empty level, right?
Try just a rough remake of the level, and keep your eye on the fps as you go.
I know there are problems with UE5 and 3000 series cards at the moment, I guess it could be related to that.
If you’re totally stuck, you can PM a link to the project if you like. But I won’t be able to take a look until tomorrow late. ( If you want to do that just migrate the critical parts to a new empty project and zip it ).