Hello GretchenMa,
Thanks for reaching out to the Apple Support Communities! It sounds like you are having issues using your AirPods when you make and receive calls on your device. Does the same thing occur when you use your AirPods to make regular phone calls using FaceTime or other messaging apps?
First make sure your iPhone is running the most updated iOS version available for it: Update your iPhone, iPad, or iPod touch.
Try resetting your AirPods next and then test them out afterwards: Reset your AirPods.