Upgraded to a Panoramic wifi gateway modem, wifi works, voice does not

I had a modem for my Cox services (wifi and voice) for about 5 years. It died and I "upgraded" to a panoramic wifi gateway (model CGM4140COM). The only change was switching out the devices. When I try to use the phone, there is no dial tone. I checked all the physical connections, the cord from the phone to TEL 1 port, the wifi works, but the voice service with my phone does not work. I can view the missed calls online in my account data though. I reviewed the troubleshooting steps listed online and used the online assistant, to no avail. They scheduled a tech to check it out, but I'd prefer to fix it before that occurs. Any ideas on what it could be?