Villager Stacking Messing up Trades

I only noticed this recently since we got a villy spawner, and beforehand my team was mostly using villagers we bred before stacking was implemented.

When villagers stack, it will sometimes remove trades. For example, Clerics (purple) are supposed to have these trades:



All clerics have these trades, the only difference is the amount at which you can trade. This range is included in the screenshot. Upon unstacking five or so clerics, however, the first tier of trades (zombie flesh/gold) was missing, and it had skipped to the second tier.

Since I'm pretty sure this isn't intended, here we are. This does indirectly nerf villagers by taking away some of their usefulness, but once you have a villager breeder up it doesn't matter as much.

Upon more testing, I'm pretty sure I figured out what's happening (album below):

This stack still had the tier one trades for clerics. Upon killing one of the stack the tier one trades vanished. I also tested this on Blacksmiths and Librarians with the same result. Killing more of the stack afterwards does not erase any more tiers.

I'll be doing more testing and updating this bug report if I find any new bugs with stacking and villagers.


UPDATE:

So it turns out splitting the villagers also messes up the trades, meaning that only the first one split will ever have the tier one trades. This is really bad - it means that once a stack is created it 'erases' all the tier one trades from every villager in the stack except for the first one split off.

On our island we had a few clerics that were unstacked and had all trades beforehand. Somehow they stacked (they were unnamed but seperated) and when I split one off the stack had the first tier of trades erased, same as above when I killed one of the stack.

 

I've updated the bug report with more information. I hope this can help the dev figure out what's going on.