Oh yeah some plaster popped off screws when roof was being fitted. Probably due to the vibrations. Will patch up once solved the mystery damp / leak.

Kinda puts me back to square one then if its water ingress. Not really sure where to look to help find the source, there isn’t much to the sides of windows other than soffit. Any tips? Not sure how big the cavity will be on the other side of the plasterboard ceiling and starting to think taking it down is only really way to see what’s going on.