5.1 Moving assets takes forever or crashes Editor

Moving assets in the editor starts to take forever or crashes. Any way to improve performance? Im making something simple for now (office towers with basic shapes).

The lighting is wonky too. Like i see it glitching through walls. The buildings dont have any windows for light to get in.

every move it will say “Rebuilding BSP” and the entire editor hangs up.

Running around in the editor, i don’t get any issues.