Freeze on cold start

[Didier B]

I re-installed the TCP connection, pfeww it is good to get a reliable fix !

Dears, I have to explain you that my GNSS antenas (I uses 3 of them) are located right under a roof window (Velux type) with a perfect sky view.
In the past three years I have never experienced the smallest signal weakness, so antennas, their location and receivers are OK.
The weak point could be USB Hubs, it is not that, I checked with a direct connection of the receiver to the RPi, without any change.
I also checked with U-center connecting through the same Hub, see picture below.

When freshly reinstalled, well at least OpenCPN (erased directory) and Signal K, everything seems OK, even after a number of stop and start the RPi.
Once the Pi has been stopped for 1h or more, on restart : BANG !
(in that case GPS signal needs more time to show up, and signal as displayed by OpenCPN gets crazy,
only when using a Signal K connection,with no view of NMEA flow ...

I would suspect an overflow phenomenon as it doesn't show off after a fresh install but only after a while ...