Farmer Villagers change profession AFTER trading

Greetings,

I have not found any information for this type of behavior so I am creating a post.

After setting up a Composter for a Villager to claim and a Farmer taking up the job I traded with them until they reached the Maximum level 5. After a day I came to trade again only to find out I now had a level 5 Butcher although I had never traded with one. A smoker did indeed exist nearby for decorative purposes.

Frustrated I bred another villager to replace my farmer. After a Farmer claimed the job site I traded again just once to lock him, but after coming back I had now a Fletcher with the amount of exp a villager gets after just one trade. Needless to say I did not have a Fletcher either I had traded with, although the Fletching table did exist somewhere further away, again decorative purposes.

Expected behavior: A Farmer villager (or any villager) retains their profession after trading

Observed behavior: I end up with locked villagers of other professions because the Farmer changes post-trading.

An interesting note is that this does not happen with any of my other villagers (e.g. my 3 Stonemasons, or my Shepherd)