This has been a problem for a while, Xfinity has the high-speed fiber but the only routers they supply were emerging apptrash for a while, then recently got even worse with none or almost none of the features accessible without a phone any more.

Your best option is to purchase your own cable modem/router and quit renting that garbage hardware from Comcast.

Or kick them to the curb and go cableless using Verizon with a router that's worth paying for.