Thanks for your help,
The "cat /dev/rs232" displayed the strings that came from the NTRIP device (OxTS RT3000):
It looks Ok, I verified the data at https://rl.se/gprmc,
I also saved the output of the cat command to a file and imported it into https://nmeagen.org/
The data that was recevied seems ok, the point were displayed in the correct location.
so the communication with the NTRIP client via rs232 was verified and is OK.
That was the receiving side (from the NTRIP device), perhaps the transmitting side (to the internet service) has a problem,
Is there a way to see/debug the traffic that is being sent to the mobile access point?