Sometimes employed villager grunts unnecessarily/even when having enough resources to trade

OK I don't know whether this is intentional or not but the grunt sound should be used only on villagers that cannot trade or if you attempt to trade with not enough resources

How to reproduce:

1: find a village

2: find an employed villager

3: assume you want to trade with a farmer and he wants 22 carrots and 20 wheat, so get the required items and come back to him

4: give him the required items in any order

5: if you pick a trade a second time, the villager will grunt regardless of number of items WTH

shouldn't it be agreeing when you have enough of an item and disagreeing when you don't have enough or if a trade is disabled