teams SEND button not functioning

Question

In TEAMS Desktop App and the Web Based one, the SEND button does nothing. A very brief circular timer flashes on screen, but then nothing looks to have changed: same meeting config page remains. In Old Outlook, tried Teams as an Add-In but Teams Meeting button is greyed out. Think that's to do with it being a Personal Subscription.

Of note, have an AVG Anti Virus / Internet Security / Anti Track tools operating. Tried with as much of this disabled as possible... still no change.