you probably have cascaded shadowmaps enabled already?
alternatively you could try to use a reflection capture probe for the interior, disable the sun and atmo fog temporarily, set r.DiffuseFromCaptures 1 and update the captures, then reenable the sky and atmo. not sure if any of this helps tho
I created a new project today, re-imported my assets and code, placed my objects and now there is no issue, I’m not sure what went wrong in the old project… but for now it is working, I will continue to build up and try to keep track of any changes I make just in case it happens again.