So I've relentlessly troubleshot my villager trading hall in which my new villagers will take upon a profession, but if their corresponding block is broken, they won't drop the profession for a new one. 

I haven't been trading with them

They haven't had any work blocks assigned to them except for the first one

I've only been breaking work blocks during the villagers "work hours" and trying to get them to change profession again

I've tried removing all job site blocks on the server within a 100 block radius trying to reset them without any result