Cannot reorder new blocks on nested block editors

[antonioribeiro]

Description

It works partially, you can save and restore the blocks, it's just that when you try to drag an drop an inner block that was just added, but not saved yet, the block comes out from the inner blocked editor to the outer one.

Looks like we have a frontend regression as this was working before.

Steps to reproduce

• Create a block editor inside a block on a another block editor.
• Add multiple blocks to the the block editor
• Update
• Refresh
• You should have the list of blocks, this works fine
• Add a new block
• Before saving try to drag and drop to move the block up or down
• It moves to another block editor, not the same

Expected result

Keep the blocks on the same block editor.

Versions

Twill versions: 3.3.1 and 3.4.1