We had the same in our 2012 17.56, apparently if you owned it from new Jayco would supply a new hard lid at no charge, if you were not the original owner stiff bickies. ours came and went with the weather and as much as it peeved me off we just left it, there was a problem with them back during manufacture apparently, they can be ground out, filled, then sprayed with gel coat then sanded then polished (probably why i left it) A good marine fibreglass repairer would be the best person to fix it