@Jvv_00 Hey, sorry havent replied for a while been busy at work.
So its definately a weird issue. I would try going into the project settings and make sure your using shader model 6 (Type SM6 into the project settings), also make sure you have direct x 12 enabled.
I would have thought they would all be set up already but its good practice to check.
Now try turning off ‘virtual shadow maps’ in the project settings. I’ve had weird shadow issues before due to VSMs. They are awesome for performance, but can leave weird artifacts.
Let me know how it goes