The villagers do not drop their profession when break the job block. (They have not been traded with so not locked)

Also when place new job blocks they do not switch. When place existing job block trades are not reset. Essentially its like they are locked pre trading.

The world was created in 1.20. Cannot say if problem existed then just that it does in 1.20.1

Incase relevant. This is in an iron farm so not in range of any other job blocks from another village. Nearest village is 700 blocks away.  Early game so dont have job blocks in base.