Villagers won't stop breeding, no baby

My villagers have been breeding nonstop since around snapshot 19w8, but they're not actually producing any baby villagers. They've become lazy and unproductive because all they do is breed but they aren't even doing that successfully. Not sure what the grey particles are but they come out every 3-4 times hearts come up. I haven't found another thread about this but this bug has persisted through various snapshots.