I made a video of this issue.
Basically there is some meshes and actors that under certain circumstances provoke flickering. The first example is kind of subtle but the second example is way too much bugged.
And then if i pass the zone with the problem and load again the level is fine.
Worth to mention. If you begin the level bugged and com back to the world map without moving to the next zone, when you enter the flickering persiste. It fixes only when the zone is completely show and move away from it
No Static lighting, no dynamic lighting. No light s at all… Only unlit materials/