Using an Microsoft 365 E5 developer account.
When using the Graph API explorer, I am able to get all calendar sharing permissions that I've set, including those that specify to share with individuals outside my organization; for this first case I use
https://graph.microsoft.com/v1.0/me/calendar/calendarPermissions
However, when I switch to using app I have registered under Azure Active Directory, with the application permission "Calendars.Read" granted, I am only able to read a single calendar permission which was there by default, which notably has the property "isInsideOrganization": true. For this second case, I need to use:
/users/{id}/calendar/calendarPermissions
Am I missing something that would allow me to get all the calendar permissions, including those with "isInsideOrganization": false? Or is there a difference in access allowed because these two cases show the difference between "delegated" and "application" api permissions? Is it possible to get all the calendar sharing permissions via application permissions?