Materials are wrong when rendering

My problem
I made a level and everything looks normal in the preview:


But when I tried to render it, this happens:

Attempts to fix
Then I tried a few things and the Texture Streaming option fixed it partly (not as much textures are wrong, but now missing).


When I restart UE, then I have the same problem as in the render, but baking lighting or geometry fixes it in the preview.
I made these models and their textures with Blender and exported them to UE 5.3 (same in 5.1), but it only works in the “preview”.

Personal Rage
I literally changed from Blender to UE5, because I thought it would be faster to render and I can make more animations in a shorter time, but with all these bugs I’ve encountered, I may just switch back to Blender, because I’ve literally spent more time working around bugs (bc they’re apparently unfixable) than being creative.

I’d really appreciate if anyone could help.

Well, I found a “workaround” while actually not trying to solve THIS issue. I just wanted the light baking not to take 30 minutes, so I enabled “Force No Precomputed Lighting” in the World Settings. Then rebaked and this just solved the issue…
But I read, that you have to make sure, that the sky objects and other lights have to be movable.
It’s not really a solution, because it didn’t fix the issue at it’s core, but at least it works.