1. I’ve installed the WP Crontrol plugin. In the WP-Cron Schedules overview I see the following. There is the fep_ann_email_interval schedule that should run every minute. In the overview of Cron events that you can see here, I don’t see any events related to sending announcement emails.
2. Template is selected, subject is filled in, content not (because of template).
3. Done.
4. Done
5. Server logs are not showing any errors. Also, wordpress logging is not logging anything.
6. Added define( 'ALTERNATE_WP_CRON', true ); to wp-config.php but no change.

It’s really strange, you have any other ideas?