iPhone not showing mobile boost after upgrading plan and adding a line

I upgraded my Xfinity mobile plan to mobile plus and added a line & new phone 17 pro for hubby, now my iPhone 13 no longer shows the Xfinity mobile boost only his does, Xfinity mobile & Xfinity internet both said they cannot fix this what do I do now? AI and co-pilot said to call them, which I did but neither the Mobile department nor the internet department could fix this, they kept telling me to turn the option on for my iPhone 13 in the App but there is not option to do that, one rep said it's because Xfinity Mobile & Xfinity Internet have to activate it. I spend 8 hours on the phone & on chat and got nowhere, HELP!