If you open the inventory and it hovers over an item as it opens, it'll quick swap the item if there's a spot in the hotbar.

How to Make It Happen:

1. Start a world
2. collect an item
3. Hover over the item
4. Close and Reopen the Inventory

What's Expected to Occur:
the inventory should open, with everything staying where it is, no quick swap unless you hit the button again.

I tested this with just mod manager, the controller mod, and fabric api.

Can reproduce, this happens because the open inventory event happens on button down and the quick move event happens on button up i think.