Unable to list or remove users in release channel

Trying to manage our release channels for a live app on App Lab using the Developer Dashboard. It looks as if there's a bug recently introduced in release channel managment. We can't see or modify the list of Subscribed Users. See below screenshot:

Note that we have 25 "Subscribed Users" in the selected tab, but "No Subscribed Users" in the list. Obviously when we select the tab we should see the users in the list, so that we can edit the list.

Pretty serious bug here, please advise?