I have been running 3cx 11 SP4 for about a month now. I have 2 POTS lines running into a Patton Gateway and 2 additional numbers provided by CallCentric. I am using a mixture of Polycom and Yealink phones. In the last week, I have had 2 instances where a call received on the POTS lines were not picked up by the Patton Gateway. Currently, my business still has a non IP phone hooked up in parallel to the Patton gateway to make sure all the calls are actually ringing through to 3cx. In 99% of the calls that come in, the non IP phone will ring once, and then our digital receptionist will pick up the call. In these 2 cases, the non IP phone would ring and my receptionist would have to answer the old phone. In both cases, I immediately called both of the POTS numbers and was directed to the digital receptionist. I would guess this is a problem with the Patton Gateway. I used 3cx to generate the configuration file and for all but those 2 cases, it has worked flawlessly. Has anyone encountered this problem?