I have seen that some people have reported this issue or similar and they have been closed, and I was having it on version 5.3.1. I read that issues should only be posted about version 6.0 so I decided to give it a try.
It still has the same issue. I am not intending on using 6.0 either since it doesn't seem like a good idea to update mid-playthrough since it empties my village created with the crystal ball and breaks other existing villages/villagers in general, it is also no longer compatible with 'Damage Indicators' like in 5.3.1 it would display their name rather than entityvillager.

Anyway, The MCA careers do not match the minecraft careers shown by HWYLA, and their trading inventories would suggest that hwyla is correct. I'm making my own village and I tried to use the Villager Generator to spawn villagers with specific professions and inventories but they immediately get overwritten by MCA and mostly set to farmers (some fishermen and shepherds but no others) regardless of what MCA says their job is.