How do you structure small group calls so people don't just sit on mute?

High attendance is easily one of the most misleading community metrics out there. A crowded room where everyone is muted with their cameras off creates almost zero actual connection.

We tried switching to intimate roundtables recently but the hardest part was getting people past that awkward initial silence. If you don't explicitly prompt everyone with a specific problem to talk about right away, people just freeze up.

For those running small interactive sessions what ground rules or conversation starters do you use to force active participation without making attendees feel put on the spot?