@Johnny I'm having the same issue. The Voice2Go works very sporadically. I have a Samsung Galaxy S8+ running the xfinity connect app and a netgear c7100v modem. Which smart phone and modem do you have?
We have the same phone, wonder if it has something to do with the phone. Has for the modern not really sure it's the one comcast (xfinity) issues. Wonder how we can find out if it's to do w the phone. Worked fine with my S5.
It's like you said it works sporadically, I was at Verizon this morning they call my home and it rang my cell phone three time, then I recieved three other calls after that and it worked, but I can almost bet it won't work the rest of the day😐