[cronjob: report scheduler] issue with report not sending daily or weekly

Your software
My Mautic version is: 4.4.1
My PHP version is: 7.4.30
My Database type and version is: 10.2.44-MariaDB-1:10.2.44+maria~bionic-log

Your problem
We have several reports to go out daily/weekly.
Our cronjob for report scheduler is set to run every 30min. (This is working)
No reports are sent.

Questions

  • do reports only generate when there is data?
  • Would be good to understand everything around scheduler to get an idea where we can troubleshoot, as we have nothing to work with.

These errors are showing in the log:
Nothing

Steps I have tried to fix the problem:
Checked cron logs, and the scheduler is running.
Manual sends work.