Owner of Chat can no longer send messages after upgrading to new Teams.

I have a user that created a chat for his team in office, and he says after upgrading to the newest version of Teams he no longer can send messages, he can only "post".

The Message Bar is no longer visible, there is only a (+) symbol there with the ability to "Post". 

Is this how we are going to be doing messages going forward, or is this a bug?