This has been discussed in the App General forum but it was suggested to post here as well. For some accounts (not all) a isolated Diablo 2 icon has appeared on the far left side of the favorites bar that can’t be unselected or moved like the others, and is segregated with a vertical white line. This appearing seemed to coincide within hours of the D2 beta release. A screenshot is provided below:
As you can see, the button on the far left is what I am referring to. It can’t be removed. If you click on it, it then defaults back to the one listed in the favorites portion.