Not so much as a 'bug' as such but it is something the dev's may have overlooked. Figured I'd submit one that I can't seem to find anyone else discovering so far by searching. If this has already been submitted and I just can't find it or if there is a method of avoiding this in the commands please feel free to ignore.

What I expected to happen was:
Villagers to keep their custom trades (given to them via /summon command tags) when the villager is placed near a 'job site', specifically the new interactive blocks like composters, blast furnaces, etc.

What actually happened was:
The villager takes up the empty 'job' from the block and they change skin (which I don't really mind) and have all of their trades replaced by ones that would suit that job.

Steps to Reproduce:
1.  summon villager with custom trade options.
2.  place a 'job site' item somewhere around said villager
3.  sometimes it doesn't happen but if you quit and reload the save it will.

1. place a 'job site' item.
2. summon villager with custom trades
3. villager will have trades for a few seconds but then be assigned to the job site and get new trades
4. same again, sometimes does not happen but will if you quit and reload the save

images attached.

Edit: finished post I accidentally made too early