Hello, we are in the middle of a new pool build in North Tx. They installed the flagstone coping last week and we have noticed 4 stones with cracks (several that go all the way through) and one that has a crack in the mortar underneath and it sounds hollow when we knock on it. Actually several sound hollow but we only see the one with the crack in the mortar. We have brought the cracks to our project managers attention and haven’t received a response. I worry about the cracks later when water/ice affect them. One is a horizontal crack that goes all the way across the stone. But I also worry that insisting that they replace them could affect the overall integrity of the pool since it’s already set. And I worry it won’t look good either if they replace them after the fact. Mainly I don’t want problems down the line, and don’t want to move forward with pool completion until we have a resolution. Please see the pics and any advice would be appreciated.