I'm in the process of migrating all of our mailboxes to 365. I've not had any issues with migrated users being able to access/modify resource calendars that had not been migrated (as long as the resource's AD account was synced to 365) until today.
Over the weekend I migrated the users of one of our regional offices. Today one of them said they couldn't edit the conference room calendars for that office. I figured that I needed to migrate them anyway, so I did.
It's been over an hour since their migration completed, but the user still can't edit the calendars. What's worse, neither can I.
I ran Get-MailboxFolderPermission against the conference room :\Calendar and see that I'm still set as the Owner, and the other users that need to be are still set as Publishing Editors. We cannot however make any changes. Double-clicking on a space in the calendar gives the following error:

Right-clicking on the calendar and selecting Properties does in fact look like I have no permissions (I only have General and Summary tabs).
I used PowerShell to try to re-apply permissions but it said no changes were made (since the permissions are already there). What else should I look at? I can also confirm that it does not work via OWA, either.
EDIT I've also logged into the mailbox with Outlook and confirmed the permissions shows the same information as the Get-MailboxFolderPermissions output (but still won't allow those users to make changes).
