We had a tiny hole that was repaired on our fiberglass pool that is only a year old. It was not leaking but assumed it should get fixed . The manufacturer sent out a repair person as a goodwill repair for the dealer. The pool has now been refilled and this is how it looks. The edges seems to have a cloudy haze on the gel coat. The repair person said we can try wet sanding with 800 grit sandpaper. Any ideas what would cause this or if it’s safe to do? Will post photo