1. flange rests firmly on tiles? Tile is strong enough to hold flange.
2. toilet rests firmly on tiles?
Toilet rests on its perimeter, not on the flange. Wax makes up the difference in space there. Weight of toilet does not stress flange or pipe.
Action to take:
1. post picture of flange in hole. Where do bolts go?
2. wait for someone else, who has set a lot of toilets, to come in and comment.