You may not be subscribed to the calendar they're scheduling it with. Generally, you can't see calendars of units you are not a member of. So, it might be getting scheduled by another ward.
If the event is not showing up in the building's calendar, then they're using another platform and the leadership should tell them that the schedule is invalid.
Note that there's a tool for planning youth events. It has the ability to simplify putting things on the calendar, but is doesn't automatically do so. Users may not realize they're not scheduling things.
Have you searched the
Help Center? Try doing a Google search and adding "site:churchofjesuschrist.org/help" to the search criteria.
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