by Dominique Palumbo.
Hi,
how you're sure that the task scheduler work well ?
Emails were send and other scheduled tasks by Moodle are done ?
Do you verify the other criterias to make course backup ?
Maximum number of backups kept backup | backup_auto_max_kept
Delete backups older than backup | backup_auto_delete_days
Minimum number of backups kept backup | backup_auto_min_kept
...
Maybe also the date on your server.
Bbasic but....