This is an intended use for the Item Placer actually. It is meant to display a 3D static model of the item you place inside of it (a request that was wanted for a long time by creators).
Removing the array here would be the fix.
In your use case I would suggest using either an item granter or item spawner.
Since the item granter doesn’t have a class filter(yet?), you can add a trigger device to first filter the class then grant the item through the item granter!