Lighting issues

Good evening at all

I’m new at UE and I just want to reproduce my old basketball court.
I made the project with archicad 2023 and saved it as .datasmith file (using the grafisoft tool)
I’m having issues with lights, in some poits I have my wall just “splitted”


i know that wall is made by two different stati mesh, but they hould have the same lights…

Second point: colums are extreame brighther the the wall and the darker room shows strange spots


thank you in advance for your help.