I have this issue as well. I had an xfinity landline for several years with no problems, then several months ago switched to a VOIP service which I wasn't happy with. Last month, I switched back to xfinity (after having upgraded to a faster internet package with new equipment as well -- coincidence?) and am also unable to check voicemail using anything other than direct dialing from my home phone. I also get the "Voicemail is not enabled for this number" message when I look at my service online. Very frustrating.
Hello, jeglover. Thanks for reaching out to us on the forums. I apologize to hear you are having issues with the Connect app and the voicemail portion of it. It's certainly a great tool to use when you don't want to be on the phone to hear the message. I would like to look into this for you. I see you have already sent in a PM. I will continue to work with you through there.
I'm glad I was able to assist you, jeglover. It was a pleasure to work with you and appreciate you being part of the Comcast family. If you ever need further assistance don't hesitate to reach out to us.