New Meeting Experience under settings in Microsoft Teams enabled. when using chatbox and click on the ellipses, the messaging extensions button is not enabled. I see it, but not able to click on it.
Turn off 'New meeting experience" and the messaging extensions work normally.
Huge impact for Teaching and Learning on our EDU tenant.
A F commented
We are seeing this same thing in our EDU environment. Teachers can see the message extensions when not tied to a specific channel, but most of them have their daily class meetings in their designated class channels. Microsoft, please fix it :)