We have a hybrid O365/Exchange environment w/ DirSync. All of our users now have their mailboxes in O365 Exchange Online, so our hybrid connection is basically just there for when new users come along. We have created some new rooms in Exchange Online to use as shared calendars for things like conference room scheduling and staff vacation tracking.
The calendars open just fine for everyone - and, as someone with full access permissions, I can manipulate the calendars, add new appointments, etc. I have added permissions to the calendars to give people Editor rights, so that those people can add new appointments to the calendars as needed. Both the calendar permissions in Outlook and O365 show that these people are listed as Editors. However, none of them can add a new appointment, edit existing ones, delete, etc. Office365 provides no...