My AirPods Pro cut out during a phone call on my iPhone 11.

My AirPods Pro cut out during a phone call on my iPhone 11 at least once per day. I can hear them but they can't hear me, so they end up hanging up on me. (That's pretty inconvenient when you've been waiting on hold!) Sometimes on video calls it also cuts out. Taking them in and out of my ear resolves the problem, but by then it's too late. Is there a fix to this, or are they defective and need to be returned?