Strange shadow render

Hello, I am having issues with strange shadows while rendering. Can someone please explain what I do wrog? So frustrating :weary:

Post your model. My guess is that your model lies at an astronomical distance from the model origin.

You probably don’t have every object grouped correctly.

Looking at patterns of the section cut - you have it on a wall?

Move it past the wall so there can be no confusion between whether the wall should be cut or not.