I just purchased a Peplink 20. My goal is to have my cable modem as primary internet connection and then a USB 4G modem as backup. The 4G modem works great. It connects and I have internet access. But WAN1 will not connect at all to my ISP (Brighthouse). I’ve got an Arris SB6183 cable modem. It works fine with my normal router which connects and gets an IP in seconds. I’m doing the very minimal connection - USB 4G in USB port, cable from cable modem into WAN1, and 1 computer plugged directly into Peplink. Nothing else connected. The WAN1 port just stays in a Connecting state for 5 or so minutes, goes Disconnected, and the tries Connecting again.
I’ve messed with port speeds, 1Gb, do not advertise, as well as MTU to Auto. It never connects and never gets an IP address. Any suggestions?