Shift-right clicking on an Entangled Block will show it as being unbound and the link will actually be broken - the issue is that information mods like Jade and creative mode's middle mouse click/block pick button will recognize the block as still being bound (and placing it down after picking it up with that will give the player a linked block). Rejoining the world will sync everything correctly and the unbound block will be recognized as such.
Steps to reproduce:

• Bind an Entangled Block (anything works)
• Shift-right click it with an empty hand to break the link
• Check Jade at the top: it will still show the block as still being bound (Survival mode's middle click function won't pick the block correctly, either)
• Middle-click on the block while in creative and place the block down: it will be bound like the one in the world originally was
• Exit and rejoin the world: the original block is now fully unbound (both for Jade and for creative and survival modes' middle click functions), while the one that was placed afterwards will still be bound

[EDIT]: Hovering over the newly unbounded block will also highlight the block destination in purple

Tested on entangled-1.3.20a-neoforge-mc1.21 on NeoForge 21.1.129