A server restarted after installing updates even with no Maintenance Window configured

Hello,

Our SCCM version is 2309.

I have the following scenario: Collection Group 4 is nested in the Collection Group 1. CG1 has a maintenance window configured for Saturday 22/06 (22:00) until Sunday 23/06 (05:00) with no recurrence.

I deployed a Windows Update to CG1 with the following settings:

• Required;
• Available time: 22/06 (22:00)
• Deadline time: 22/06 (22:00)
• Deadline behavior: Software Updates checked and System Restart (if necessary) UNCHECKED

All the systems members of CG1 applied the updates correctly and as expected. But, in the following weeks, we noticed some systems did not. So, after further analysis, I discovered that CG4 had a misconfiguration related with one of the queries. So, i corrected the query and, of course, some systems were loaded in the CG4 and, consequently, to CG1 where the deployment was applied.

After some hours, we noticed that some servers restarted, the same systems that were added to the collections. I searched SCCM looking the reasons that allowed the servers to be restarted. There were no Maintenance Windows applied to allow any reboots during working hours.

But, the logs say that a Service Windows of type 4, although I haven't found any Service Window ID, was founded as you can see in the second image:

I reproduced the same configuration in the lab and the server did not restarted. Following are the images from the logs:

So, my question is: Could someone explain to me why that restarted was allowed and executed even with no Maintenance Window configured?

Regards,

Thiago