Users can't phone in, visibility issues

I just hosted a meeting on I selected the platform because some of the participants do not have internet capability and they were to call in by phone. The call in system did not work. The best result was the number was dialed, call answered, the PIN was entered, the system hung up. This was a critical issue, since it meant several people could not get on.

Any guidance or suggestions are very welcome!

In addition, some of the internet based participants were shunted to a “statistics screen” as they described it and then could not make themselves heard - although they could hear. Others were visible as only a green box (not sure if they were via internet). In some cases, user’s video kept disappearing and reappearing.