Why are people floating around?
Video windows moving around is because the system detects who is speaking. To solve that, click the lock icon in the bottom right of a window.
Why do we lose video sometimes but still have audio?
Video quality dynamically adjusts based on the strength of a user's network connectivity. This is done by the participants's computer sending feedback that say "My network quality is at 'x' level." The faster and more stable a participant's broadband connection is, the better the video quality it will request. If the participant quality drops below a certain amount, it will result in falling back to audio only to preserve the continuity of the session. Broadband connectivity is the limiting factor. If participant.
See this article: Common Video Connection Issues