Very hard to say without pics, but......

If the glass wet out fine (no visible weave) and there is a patch of a different colour on the wood, there was probably some oil or other contaminant there.

The glass won't adhere so well there, but if it is a small patch it is not worth doing anything about.

The only thing you can do is sand off the glass right down to the wood and then put a patch over the sanded area, but it is very hard to get an invisible transition around the edges of the patch. As it is on the hull, I would almost certainly leave it.