iPhone 8 - Others can't hear me on calls

I purchased my iPhone 8 less than a year ago. Over the past couple of months I am having an issue when I am on calls. I can hear the person on the call just fine but they stop hearing me. It happens whether I am holding the phone or have it on speakerphone. I tried removing the case and testing voice memos (which worked fine) and it is continuing to happen multiple times during a single call. I also turned off Phone Noise Cancellation and that didn't fix it either. Help!!