Phantom inbound phone calls on COX analog lines problem

I have a Switchvox SMB EDITION 3.5 system with a TDM800P and a TDM400P boards.

I have 4 COX analog lines and 3 Verizon lines coming into the system.

Every 66 to 67 minutes all of the COX analog lines ring into my system with phantom phone calls, COX does not see any phone calls coming into my lines at those times. The Verizon lines do not do this. I have put the COX line on both cards in my system and it only occurs with the COX lines. I have traced the lines all the way back to the DMARK looking for possible electrical interference and found nothing. I have put a FLUKE tester on the lines to make sure all of them are working fine and the lines come back 100% clean.

When I unplug and plug the COX lines in the system, the Switchvox system senses and incoming call and attempts to answer it. When I unplug then plug in the Vezion lines into the system nothing happens which is what should happen.

The DMARK for the COX line and the DMARK for the Verizon lines are side by side in the telephone room. The only thing I can think of is that COX is sending some type of HEARTBEAT to those line causing a change in polarity signaling an incoming call.

If a call is active on a COX line nothing happens on that line but the other ones show phantom phone calls.

Anyone seen this before or know what the problem could possibly be?