Only one client at a time (Debian, Raspbian)

[Carles Pina i Estany]

Hi gpsd users / devels,

I'm struggling with something that I thought that should "just work" - I
think that I'm miss-understanding something.

I have a Garmin eTrex 30x GPS connected using USB to either my computer
(Debian Buster) or to a Raspberry pi (Buster as well).

I installed "gpsd" Debian package and then I'm trying to have two
different software access the gpsd over the port TCP 2947:

-kplex for reading it and saving into files / send NMEA string over the
network
-qgis (which doesn't have TCP NMEA alike but gpsd)

I realise that gpsd 2947 port in Debian/Raspbian is handled by systemd
socket activation (which I've never used before... so I might be missing
something).

As soon as one software (e.g. kplex) uses it, the other one (qgis)
cannot use it.

If I do it using telnet:

Terminal 1:
pi@raspberrypi:~ $ telnet localhost 2947
Trying ::1...
Connected to localhost.
Escape character is '^]'.
{"class":"VERSION","release":"3.17","rev":"3.17","proto_major":3,"proto_minor":12}

If I go to another terminal I don't get the welcome message:
pi@raspberrypi:~ $ telnet localhost 2947
Trying ::1...
Connected to localhost.
Escape character is '^]'.

If I have opencpn reading from gpsd I cannot have qgis, etc.

I've been trying to not have systemd and use just gpsd but I had other
problems - that I can show step by step but hopefully not needed. I'm
happy to fix what I have not to replace everything.

What I'm doing just work? Should I take another approach for my problem?

Any pointer on "look there!" or "ah, change this there" is welcome.

Using: gpsd 3.17-7+b1 (all from the distros at the moment, as I thought
that is a common use case)

Thank you very much,

-- 
Carles Pina i Estany
https://carles.pina.cat