How to fix this visual glitch which causes flickering and GameObjects duplicating in scene view?

This started happening after I changed to URP , also note that the project is old from 2015 and was made in editor 5.3.1f, I changed the editor version to latest 2021 LTS community version, all other scenes are working fine with URP except this one I also tried stacking the cameras but it didn't fix the issue

Solution

Problem solved: it was the Environmental settings under the lightning settings. Although I just changed the skybox material to none, and that solved the issue, I think it wasn't in some way compatible with URP.