RTCM message not received

[ciniminis1]

Hi there,
I intend to use SKPOS provider to receive the RTCM corrections to Ublox ZED F9P module. Unfortunately, the corrections are not received due to connection dropout:

[INFO] [1724336896.510572]: Connected to http://195.28.70.16:2101/SKPOS_CM_31
[WARN] [1724336930.014829]: Reconnecting because we received 0 bytes from the socket even though it said there was data available 5 times
[WARN] [1724336931.205640]: Received unauthorized response from the server. Check your username, password, and mountpoint to make sure they are correct.
[ERROR] [1724336931.207347]: Invalid response received from http://195.28.70.16:2101/SKPOS_CM_31
[ERROR] [1724336931.208659]: Response: HTTP/1.0 401 Unauthorized
WWW-Authenticate: Basic realm="SKPOS_CM_31"

The dropout is caused by the NMEA message not being sent over, as I communicated directly with the provider, who confirmed they had not received the NMEA message. The NMEA message on nmea is published by Ublox driver with ~ 1 hz freq and contains the GGA string.
To confirm the functionality and rightness of the NMEA message, I connected to rtk2go.com provider and successfully received the corrections with the same Ublox settings. Have any of you come across a similar issue? Is there a way to check that NMEA msg was actually sent to provider?

[pondersome]

Not all NTRIP servers require an NMEA message. I don't think rtk2go.com does, so you may not have a valid test. Some servers require an NMEA message to auto-select mount points or validate compliance with service policies.

For ROS2 consider looking at the fix2nmea node provided here:
https://github.com/olvdhrm/RTK_GPS_NTRIP

Note that when using rtk2go for extended durations, the default server communication needs to be 1hz or your connection will get "sandboxed" and you'll start receiving garbage correction data and ultimately be unable to connect. I have a fork that allows you to configure the ntrip communications rate with a parameter here:
https://github.com/pondersome/ntrip_client/tree/feature/ros2_ntrip_rate_control