Missing NMEA 2000 data in Signal K Server

I have an Ekrano GX with Large Image, running SignalK. Under the Signal K data browser, I see most of the NMEA 2000 data from devices on the network, but some is missing. I see GPS data but no other Garmin data.

I have a NMEA2000 data logger on the network and it captures all of the engine data (provided by Maretron J1939 to NMEA2000 device), but I don’t see any of this in Signal K.

How do I configure Signal K to see other NMEA2000 devices?