Powerpoint embeded audio not audible for the audience

I as the host and person sharing the Powerpoint with embedded video had "Share Audio" enabled. When the audio failed during the live webinar, I checked the "Share audio" setting again and the controls were not visible. I tested the audio in the practice session and the other panelists were able to hear the audio clearly. During the live webinar, I, as panelist could hear the audio in my headphones, but the audience was unable to hear the audio. The only things different from the practice session to the live webinar were:  1. We were recording the webinar and 2. a co-host was added. Is there a setting or something missing?