Sounds like the lock locating dowel has either broken off or the lock needs undoing & relocating. Not easy as your working in a tight area.
Interior handle works on a cable that also has a locating white clip that can break with age. On back of panel, check thats all good too.
Interior handle works on a cable that also has a locating white clip that can break with age. On back of panel, check thats all good too.