Steps to reproduce

1. Spawn a villager.
2. Sell it items once.
3. Buy an item from it.

Expected result

Buying from the villager gives it twice as much experience toward its next level as selling to it, as it did before 1.16.

Actual result

Selling to the villager gives it twice as much experience toward its next level as buying from it.

There is a glitch with villagers,when trading villagers get more xp when giving them items, see the photos I have attached you will understand it better...