How can I fix audio issues on MacBook voice calls?

I use Calling from MacBook frequently, but some days the outgoing audio just stops working. The person I'm calling can't hear me. I can hear them just fine. I have to hang up and call back from my actual iPhone. I have tried rebooting and that works sometimes. It's not a regular issue. Just pops up occasionally.

Any ideas?

It's REALLY convenient to use.