[4.9] Weird shadows after light compiling

Hello everyone, I’ve a problem that I can’t solve without your help. I’ve this situation:

This preview:

with pretty good lights (but uncompiled), and THIS fter compiling:

All the assets are from SunTemple from Epic Games.
What I’ve to do for fix this weird problem?

Thank you in advance!


The problem was in the floor’s UV. I’ve used a stretched mesh. Stretching them esh I’ve also stretch the UV. I’ve solved replacind the mesh with a BSP. After the replace I’ve converted it in a mesh with the right UV and the shadows are now fixed!