To help diagnose GPS issues on a mobile client, it is very helpful to enable enhanced logging which is disabled by default.  

Applies to all environments

To enable verbose GPS logging on the mobile client, navigate to C:\Program Files (x86)\Motorola\PremierOne\MobileClient\config\logger.config (pre 4.6.9 versions) or to C:\ProgramData\Mobile Client\config\logger.config (Versions 4.6.9 and higher) and open the logger.config file with Notepad or preferably Notepad++. Make sure the client is closed.

Scroll down towards the bottom of the file or using the search feature locate:    <logger name="GPSDeviceData" 

Change Informational to DEBUG_VERBOSE and save the file.

Open the mobile client, it is not necessary to login for GPS to start streaming and the data to begin populating.  New files will be generated with verbose logging in c:\ProgramData\Mobile Client\

For better understanding of the GPS sentence, this may be a helpful resource:
https://aprs.gids.nl/nmea/#rmc

This GPS decoder is also helpful:
https://rl.se/gprmc

To visualize the GPS data, you can use Panasonic's GPS Viewer(if loaded on a Panasonic laptop, should be located in the Start Menu->Panasonic) or one can be downloaded here:
https://www.visualgps.net/#visualgpsview-content

Once troubleshooting is complete, you should turn OFF verbose logging.  Follow the same steps but change to Informational from DEBUG_VERBOSE and save the file.