"Copilot" Appeared at Top of Teams Chat, Now It's Gone

• About 1/3 of our users, including myself, have a Copilot for Microsoft 365 license.
• App permission policy allows "Copilot", but not "M365 Chat", as that is being sunsetted.
• App Setup policy does not include Copilot, because it doesn't even appear in the list to be added.

A week or so ago, Copilot appeared at the top of the chat list on the left.  Then, suddenly, this week it disappeared, and users have been asking me where it went.  Did something change?  Is it coming back?  I understand that the Copilot button can be clicked inside an existing chat or meeting, but users licked being able to chat with it, just like any other person in the list.

Just wondering if its disappearance is by design or if I have something misconfigured.