Answering suddenly not picking up with Xfinity Voice...

Hi!  Have a Phonemate 9300 Stand-alone Answering Machine connected to my Home Phone, former landline.  I like my Old Phonemate 9300 to be able to screen calls. Recently got Xfinity Triple Play, and the Machine was picking up calls like usual at 2 rings even after switching to the VOIP.  Around the time I set up Voicemail (although I think was "ON" when I got Triple Play),  with 9 rings to allow Machine to pick up,  suddenly Machine stopped picking up messages.   Even deactivated Voicemail together, but still Machine won't catch calls.  Decided to test the Machine at Girfriend's House who also has Xfinity Voice, and the Machine picked up at 2 rings!  So the Machine works, what could be causing it to not pick up messages at my place.  I even plugged Machine directly into my Modem and unplugged the other phones tied into the modem, no luck.  Have restarted my Modem thinking it would reset, but did not help.  Thought I saw something in the Forum here about "re-registering my phones" by hitting a button the my Modem and the Flash buttons on my phones?   Comcast Tech Support had no answers, Machine should work esp. since it worked at Girlfriend's house.  Saw a post referencing "REN (ring equivalent number)", could my Xfinity modem not be putting out enough voltage to cause my Machine to pick up?  There is enough "voltage" for the phones to ring.  Any ideas would be great, thanks!