Receiving Video but no Audio

I have a strange situation where Video works but Audio does not. I have Debug set to high and I don’t see any errors. I know Audio works in general because some calls do receive Audio.
I did turn on RTP debugging and I don’t see Audio flowing to the UA.

Is there anything (error) in particular that I should be looking for?

Thank you,

Do you use a softphone to make the call? If yes which?

Yes, the ZVRS/Purple Z5.
It is very strange to me that Video works but not Audio.