When I get an incoming call on my XR people can’t hear me when I try to talk. Phone keeps cutting out.

See this for troubleshooting, If the microphones on your iPhone aren't working - Apple Support

If this does not help, then use the Get Support link at the top of the page here to contact Apple Support to schedule service.

Click on the blue text in my response. It provides you with troubleshooting steps.

So, I'm guessing, but the Voice Memo and the Video all worked? If the call does not work, then use the Get Support link at the top of the page here and contact Apple Support about service.