Kplex lost contact with signal k

[Littlechay]

I'm not sure if this is a bug or a feature but I don't think that it's finger trouble.

I noticed that OpenCPN was no longer displaying data from my I2C or 1W sensors. I restarted Signal K, restarted Kplex,. Nothing.

Rebooted, nothing
Shutdown and started, nothing.

I can see the data in signal k, temperature, pressures, roll, pitch, heading etc..
But can't see anything in the diagnostics of the entire in the NMEA 0183 window.

I have a serial GPS and that is being passed by Kplex and is being shown in OCPN.

How do I debug Kplex , or Signalk?

I've run openplotter from command line and there are no errors.

Sorry no internet as such to go hunting online at the moment as I'm on the boat.

OCPN is 4.6.1 and OP is 0.13 i.e. the latest updates as performed via Openplotter's update interface.

Cheers
Chris.