Host unable to hear participants

Hello,

I hosted a conference using this platform and we planned on using a mix of VoIP and Dial-In for the conference. However, although all microphones were turned on for the participants, and our speakers were on, we could not hear the participants nor could the participants hear each other. However, everyone was able to hear us (the hosts). Eventually we just switched to everyone using the dial-in option over a conference phone (still couldn't hear anyone through the Connects platform).

Has anyone experienced this before and could offer suggestions on how to fix the problem?

Thank you,

Janine