Does not back up automatically

Windows Server 2008, which is an Urbackup server and is also its own client.
I set the schedule to run from Monday to Friday at 19:00 (Mon-Fri / 19: 00-20: 00) but it does not start the backup, it’s like nothing happened. In the server interface it shows the ones that have been accessed and if I ask to back up manually, it does. Has anyone ever seen this kind of behavior?