After messing around with it for a few hours it suddenly started working. I changed nothing about the farm. Not sure what did the trick, but I'm closing the ticket.
Through testing I discovered that Villagers can now only detect doors within the same chunk they are in. So if a village isn't properly aligned, it will never spawn golems, no matter how many villagers you add.
After messing around with it for a few hours it suddenly started working. I changed nothing about the farm. Not sure what did the trick, but I'm closing the ticket.