Minecraft Version

1.20.x

Forge Version

47.2.1

Vampirism Version

Vampirism-1.20.1-1.9.2

Modpack

No response

Singleplayer/Multiplayer

Server

What happened?

In the vampirism mod there is a mechanic of Titles (from Baron to Prince), it opens after the 14th level of the vampire. And is upgraded by completing tasks from the “Vampire Representative”
In addition to tasks, it requires certain items to be completed that are exactly the problem.

If there are more items than needed (in one slot) - they are not spent, but an increase occurs

If there is the right amount of items (but they are in different slots) - they are not spent but an increase occurs

If there is the right amount of items (and they are in the same slot), they are spent and an increase occurs

mob's meta vampirism:task_master_vampire

Relevant log output

No response

Reproduce steps

No response

Other relevant mods

No response

does not count killed animals

So far I am unable to reproduce this (Same versions, server).
I assume you are using bukkit here as well? Maybe there is some issue.

Are the items still there after re-connecting to the server?

We re-checked, things are being wasted. But the progress of the task from the vampire task master does not count killed monsters and hunters. Also, completed tasks such as “Trade with villagers” or “Raid`s” are not counted.