kplex cannot initiate interface signalk

[dominiquehausser]

Hello
I have install openplotter on RPI 3B+,
All data are provided by the BOX NKE via serialUSB : no problem to get them on opencpn directly from serial.
I have a laptop and I was surprised not be able to get the data via TCP server port 10110 from the RPI.
After some investigation I discover that kplex cannot initialise interface signalk, by mentionning cannot opening TCP server as (null)/30330 is already used.

Very rarely and without apparent reason the interface signalk is initialised and I can the data through tcp server on other devices.
The problem is the same on the 2 RPI I have on board, they are used for different purposes, the configuration I made did not concern signalk or kplex.
Any idea in which direction I should look to correct this problem.
Have a nice day