Audio issues

[DKM]

I give music lessons (instrumental) via Zoom on my iPhone. Everything has been working quite well since the quarantine days until now. In these past few months, neither the students nor I can hear one another's instrument. Speech remains absolutely fine. My students typically use laptops. (We have finally resorted to FaceTime.) 

My husband and I experimented today using his laptop (and my iPhone) and the same thing happened. Instrumental sound does not come through. (My desktop is not in an amenable place in the house for lessons and the iPhone has been quite fine up until now.)

My iPhone has the latest version installed (not of Zoom, but iOS). Has Zoom been updated in the past 3 years and is that what I need? 
Thanks for any assistance!

[centralagnewark]

My audio is not working on zoom