High pitched screeching in Airpods 4 Microphone on calls

I bought Airpods 4 for my sweetie a while back. When we talk on the phone, if she is silent, any little noise in her background is picked up as a high pitched squeal through her mic, it's almost unbearable. We also have Airpods 2 and they don't have this issue AT ALL. I have scoured the web and there is almost no info on this issue, the issues posted are more about muffled mics, not this ridiculous screeching through the mic.