Hey!

Is it at all possible to stop the movement of certain items within an inventory? Such as a star but they can move anything else.

Many thanks.

Yes, you can add the inventory-modify itemflag to the item.
itemflags: inventory-modify, self-drops, death-drops for example.

A full list of itemflags can be found in the wiki here; https://github.com/RockinChaos/ItemJoin/wiki/Creating-Items#defining-an-items-itemflags

Thank you very much! I will now close this :D