When I open the `More added apps` ("...") menu, right click the bot and select "Unblock", nothing happens. I cannot communicate with the bot because the chat bar is grayed out and says "You cannot send messages to this bot because you've blocked it". Every time I try to unblock it, nothing happens.
Conclusion: I think the `Unblock` button is broken.
PS: The same problem happens in the web version of teams.