Have an unusual one here. 2020 Giant Trance carbon frame with a two bolt seat post collar (seat post clamp) and the stock Giant dropper post. If both seat post collar clamp bolts are torqued to spec at 5nm the dropper post goes down, albeit with some effort, but won't come back up. If both bolts are torqued to 4nm the post goes down in the same manner, and comes back up, but not all the way back up. Falls about 1cm short of full extension. If only the bottom bolt on the seat collar is torqued to 5nm and the top bolt torqued to 1 or 2 nm then the post works perfectly. This started happening after the customer lowered the post in the frame.
My thoughts on this is the top edge of the seat post collar is putting excessive pressure in a localized area on the post when torqued to 5nm and deforming it enough to cause the problem. Does this sound reasonable?