Oh wait – now that I can see the video (I overlooked it earlier...) I guess you're suffering from old behavior. Unlinking can be a bit difficult, since it's possible to have multiple links from one item (I know, yours is the other way around, but bear with me). Use the Delete or Backspace key to remove it.
The idea behind it, that disconnecting the handle would remove all connections and triggers (a new feature). So you have to select the line or that moving dot, and delete it by using a key. Yeah, it's very silly, but the developers thought it would be nice to throw us off a bit, here. 😉