No internet via internal 4G/5G modem

Hello All,
I have a new ZBT Z800AX router, factory-installed OpenWRT, and an internal Quectel RM502q-AE modem. It is running Chaos Calmer 15.05.1

WiFi configured, working correctly. LAN ports working correctly. The modem shows up under Status > Overview. It has good signal strength, status is "Ready" and the ISP correctly shows "Verizon."

However, there is no access to the internet.

Under Status > Load Balancing > Interface, it says "Interface: 4G Status Disabled"
Under Status > Load Balancing > Detail, is says "Interface 4G is offline and tracking is down"
Under MWAN Status - Diagnostics there's an option to ping the default gateway. The message returned is "No gateway for interface 4G found."

So, something is missing or configured wrong. I would appreciate any suggestions.
Thanks, Mark

Ask ZBT, you're not running any official version of openwrt, the Z800AX isn't a supported device.