Some items become undraggable after dragging between groups

[BradDuns]

Issue

I've got nested draggable elements that sometimes stop being draggable.
There is an array of groups, those groups can be reordered.
Within each group there is an array of members, which can be reordered or moved between groups. The app is in vue, it syncs with firestore via a pinia store.
My app is using 0.3.1 because a few things stopped working when I tried to upgrade so I had to roll back.
It mostly works but sometimes it just stops.

A repeatable reproduction using v0.3.3 here: https://codesandbox.io/p/devbox/dnd-nested-v0-3-3-f2wkj5
This seems to reliably break draggable elements that are in a group after a group thats an empty array.

Setup

Since this is shared live data from firestore, if it doesn't look like below you can reset the state with the Reset Firestore button

[ { "name": "Group 1", "members": [ "Jack", "Jill" ] },
  { "name": "Group 2", "members": [ "Jane", "Joe" ] },
  { "name": "Group 3", "members": [ "James" ] },
  { "name": "Group 4", "members": [ "Jake" ] }, ]

Steps to Reproduce

• Drag Joe from group 2 to group 4 - works
• Drag James from Group 3 to group 4 - works
• Now all elements in group 4 are no longer draggable
• Drag group 4 above group 3 and they work again

Similarly if you empty group 2, groups 3 & 4 are no longer draggable. Drag group 2 below groups 3 & 4 or drag something from group 1 into group 2 and everything works again.

Empty arrays isn't the only thing that seems to break it but the above is repeatable so I wonder if it would solve my other upgrade & intermittent issues.