Hi Soibien,
Please check if there is other condition/trigger that might fire the scheduled task? For example there might be another user that manually triggers the task.
You can also enable the task histroy in scheduled task and refer to the steps below:
Step 1: Open an elevated Task Scheduler (ie. right-click on the Task Scheduler icon and choose Run as administrator)
Step 2: In the Actions pane, click Enable All Tasks History
Then we view the task running datetime and the user account etc.
Best Regards,
Anna Wang