Further testing reveals this issue was introduced in 1.7.7. Reverting back to SDK version 1.7.6 seems to fix this issue. However, I loose firefox support.
1.Host can able to speak and not able hear from participants
2.Participants can able to hear from host
3.Issue - participants mic showing connected but not able hear
Sorry to hear you are facing issues. I have passed this information to our engineers who are working on the issue. I will keep you updated on the progress.