Sound issues, can speak, can't hear

I have a door view cam, app is installed on android (samsung). Notifications all work fine, had some tech issues a few weeks back that needed a full reboot, no issues since. Yesterday someone came to the door and I had to explain to them they needed to leave the package on the doorstep as I was self-isolating. I could see their mouth moving but couldn't hear anything on my phone. I could hear my own voice coming through the doorbell though. When I looked at the video after, the sound from both of us was recorded fine, it just wasn't working during the live view. TLDR: Live video wasn't glitchy or buffering, just no sound. Recorded video had perfect sound.