SBFspotUpload not uploading (W10)

Just installed SBFSpot, using " * SBFspot V3 Quick Reference Windows EN 1.1

All went well, including 2 uploads to PVOutput, but then the uploading stopped. Waited for over 30 minutes, but no new upload was done (checking the log file 'SBFspotUpload###.log).

Uninstalled the sbfspotupload service, installed it again and started it and another upload was done but then stopped again. It seems that the only way I can get an upload done is to keep repeating the uninstalling and installing of the service. So, something is wrong, but no clue what is is.

Set the debug level to ‘debug’ in the ‘SBFspotUpload.cfg’, but no extra logging seems to be done.

SBFspot should run every 5min between 6AM and 22h
This can be done with scheduled task