Just out of curiosity could you clarify the following things for me:
- Do you still experience the issue if you replace your structure(just the crypt, without land mesh) with a roughly corresponding blockout made of default UE4 cube meshes?
- What happens if you place abovementioned blockout in a new default level with a skylight added ?
- What about testing your crypt meshes in a new default level with a skylight added?