Cannot delete Embedly auto-link in Discussion edits

When a user simply posts a youTube url, embedly automatically converts the url to a live youTube thumbnail. So, I am not referring to the url embed in the menu of embedly. Those work fine.

For some reason, on the Timeline, the url is not converted BUT once you go to the actual post, it IS converted to the youTube live thumbnail.

In Edit mode, the Delete button has no effect. Click it and nothing happens. The result of the failed Edit is a duplicate thumbnail of the youTube link.

Thank you!