Chickens eating eggs

I don’t know how it started but I’m down to 2-3 eggs a day. I tried mustard, blinders, I even separated what I thought were the two main culprits but they’re all doing it. The only reason I’m getting any eggs at all right now is because I think they’re getting enough oyster shell that the eggs are too hard to break. I have rollaway boxes but they mostly stopped using those for whatever reason. I have 10 more chickens to introduce in another coop but I don’t want to move them in until the behavior stops. Any suggestions?