Shout out to @pigletjohn but also I know there are others out there so I'm grateful for any advice.
We just saw a patch of damp inside - last rain was about a week ago and wall is dry-ish but clearly damp up by the ceiling. So we had a look outside and found this (pic below). Who fixes this kind of problem? The chimney is external and the upper part was removed at least a decade ago with the roofing redone. We did have some storm damage earlier in the year, a couple of feet along the roof to the corner part and had someone out to do the repair. We redecorated this room a year ago. It was wall papered so it's possible this isn't new, looking at the pic it doesn't look fresh. Who should we get out to fix the external bit do you think?