SAP SolMan BPMon data Collection Job issue

Dear Friends,

In our SolMan system (7.1 SP 12), the BPMon alerts are not getting triggered automatically after system restart.

Every Saturday, system will be restarted after backup. After the system restart, the data collection is not happening automatically.

I had checked the BG job "SAP_ALERT_CALCULATION_ENGINE". It got finished successfully.

Can anyone help me to find the root cause of this issue and help to fix the same.

Thanks in advance.

Regards,

Mani