advanced call forwarding

We have had Xfinity voice since 2016 or 2017. I always had Advanced Call Forwarding initialized to my cell phone so that all calls would ring simultaneously on the  Xfinity voice home phone and my cell. I have always ONLY given out the Xfinity voice number. If I am away from home, I answer the Xfinity voice call on my cell (Xfinity mobile service).

Xfinity had to close our legacy account and open a new one because of technical problems with activating an Xfinity cable modem. We have had multiple problems all of which have been resolved except the "Advanced Call Forwarding." I, with support from the local Xfinity store rep, have spent immeasurable hours with technical support to resolve this. Today, the Xfinity rep at the store (who seems very technical) put in a ticket for Advanced Support. The Advanced Support  rep called my cell while I was at the store, I explained the issue, and she said she resolved it. She called the home phone and it rang on my cell. WELL, it turns out she forwarded all my calls to my cell. When I got home, I could not answer the Xfinity voice line on my home phone. When I picked up the home phone the line would be dead. That's when I realized she forwarded all my calls to the cell.

So, I am back to square one with yet another Xfinity appointment tomorrow at 10am. Note, I am not trying to use the NoMoRobo feature that many people complain about with Advanced Call Forwarding. I just want both my home and mobile devices to ring simultaneously and be able to answer on either device.