iMac 27" 2020 shutdown schedule fails since Tahoe + unknown sleep tasks

Updated to Tahoe 26.1 (that resulted in a complete clean re-install of the iMac by a certified Apple reseller due to multiple serious problems; but after the re-install a week ago it works fine besides this:

before the update I made a schedule so the system would shut down every day at 23:00. That worked always fine. After the update I made a new schedule in Terminal. However, that did not function: system give's pop-up screen with text that it can not perform the task.

After trying to find out what the problem could be, I found that there are 3 more scheduled tasks (that I did not made) that update every time the iMac is turned on (see below; its in Dutch: it say 3 times "switch sleep off" at 3 different times, but every day the date mentioned - below 12th November - is automatically updated).

There is also the scheduled task I made in Terminal (switch off every day at 23:00).

I tried to delete the tasks with "sudo pmset repeat cancel". That deleted only the task I made myself, but not the first 3.

Tried "sudo pmset schedule cancelall", but the 3 tasks were not deleted.

My questions:

1: what can be the reason the shut down task does not work?

2: how can I make a task so the iMac shuts down again at 23:00

3: what are the three tasks that switch off the sleep at three different times and why and by who are they made?

4: Is it wise to delete those 3 tasks? If so, how do I do that?

The info in Power in Systeminformation: with translation/comment in italics

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Volgende geplande gebeurtenissen: (translated: coming planned tasks)

  appPID: 431

  Type: Schakel sluimerstand uit (translated: switch off sleep)

  Gepland door: com.apple.alarm.user-invisible-com.apple.calaccessd.travelEngine.periodicRefreshTimer

  Tijd: 12-11-2025, 09:52 (date changes every day, so yesterday it was 11-11-2025; the time does not change)

  UserVisible: 0

  appPID: 92

  Type: Schakel sluimerstand uit

  Gepland door: com.apple.alarm.user-invisible-com.apple.acmd.alarm

  Tijd: 12-11-2025, 21:22

  UserVisible: 0

  appPID: 431

  Type: Schakel sluimerstand uit

  Gepland door: com.apple.alarm.user-visible-com.apple.donotdisturb.server.ScheduleLifetimeMonitor.timer

  Tijd: 12-11-2025, 22:00

  UserVisible: 1

Terugkerende gebeurtenissen: (translated: returning events: this is the task I made myself, but does not work)

  Type: Zet uit (translated: switch off)

  Tijd: 23:00 every day