Lost capability to text: Contacts show sip:[phone number]@msg.pc.tmobile.com;user=phone

I started experiencing this issue about a year ago. It is happening with only one of my contacts who happens to be a Metro PCS customer. I, of course, am a T-Mobile customer. My friend lives in Florida. I have other out-of-state contacts but his is the only one having this issue. I have him in my contacts but sporadically, his text messages will come through from that sip:+1561XXXXXXX@msg.pc.t-mobile.com;user=phone.  When I attempt to respond, my messages FAIL! Was wondering if anyone else is from Florida experiencing this same issue? Maybe we can get to the bottom of this if we pinpoint a location/state.