The Vicious Direct Message Circle

[optimistmb]

At some point early in my meeting today, either I or this other person sent a direct message which has started a chain reaction. Now every time I try to talk in chat I send a direct message to him and vice versa. Each time this happens, it doesn't matter that we've switched to the main Meeting group chat, the system automatically switches us back. We keep trying to break the chain but one or the other of us manages to miss that we last received a direct chat. If you're thinking this is easy to resolve, under normal circumstances that would be true but this is an active class with constant chatting going on from nearly 50 people. There's supposed to be a block option but it's missing from the menu in our direct chat.

I'd like to know if there's a way for me as a user to set the Meeting group chat as the default channel which would stop me from responding to this person's direct chats. Or if there's anything else I can do. We are graded on participation and the teacher has to believe I'm simply not participating even though I have been very active. This is very frustrating.