Use #support channel in Signal K Slack (get an invite).
Get a log of your NMEA2000 bus data with something like /usr/lib/node_modules/signalk-server/node_modules/canboatjs/bin/actisense-serialjs /dev/ttyUSB0 > /tmp/actisense.log.
Share the resulting file, preferably via Dropbox, Google Drive, Github Gist or something similar so that you can just share the url.
If the console is available, go to Server -> Server Log and enter the the names of the compononets you want to debug.
Otherwise, you can edit the file ~/.signalk_debug' and add them there. For example: @signalk/aisreporter,signalk-server:udp-provider`