Bug:

Villagers from previous versions (24w11a if I am not mistaken) cannot trade with the player under the "Villager Rebalance" Experimental feature

Way to recrreate:

Create a new world in a previous version (24w11a works for the recreation of the bug*****) and enable "Villager Rebalance" experimental feature (Preferably, not the "1,21 update" experimental option).. Upgrade your world to the current version (24w12a) and the villager won't trade with you despite having the correct items (Tested with Librarians)

***Read the following 

Potential cause:

Either it is the change with the villager trades and the trial chamber map or it's the change from NBT to Components which would mean that the world creation must be in a snapshot before the transtition to Components (24w07a or before)