ghost alarm

Every work week day i get an alarm at 7:15 o'clock named "school". I know it is linked to the alarm app and not something else, because when i open the notification, i get redirected at the apple alarm app even when it is not installed. I have deleted the app, reset my settings, disabled the health app and more but all was in vain. I have been to multiple apple (affiliated) stores but no one can find the underlying problem. Does anyone have a clue on how to fix this problem?

Thanks in advance.