Inconsistent backup status after prefilescript implementation

Hi,
After adding pre-backup scripts to some clients, their backup status became inconsistent. As the attached image shows, the backup occurred recently on these clientes but the status is in red stating that there were no recent backups.
Is there a need of some output on the prefilescript.bat to get this right?

Info:
UrBackup Server 2.3.8 on CentOS 7.6
Windows clients with a prefilescript for 7z compression before backup

Thanks!

Anyone else having the same problem?
Can someone help me or is it really a system bug?

Thanks!

Have you looked at the backup logs, did the backups complete without errors?

Thank you for your attention. Yes, I looked at the backup logs and there is no error log. See below the logs of one of the servers where the problem occurs.

The last lines of the log, after prefilebackup script:

This is so strange, both the script and the backup run perfectly, but the status still displays “No recent backup” in red.

Thank you for any help.