When trying to insert an item(the wrong one) into a decorated pot, The item will disappear from your hand but will not be wasted. You can see your item again once you click the inventory slot again.

Steps to reproduce:
Go into trial chambers.

Go into survival and try to insert an item into a decorated pot.

expected:

item will get rejected and stay in your hand.

result:

item gets consumed but that's only a visual glitch.