By default, Exchange Online allows other users in your tenant to see limited details of your availability when scheduling meetings. More information can be displayed by updating the calendar permissions for mailboxes. This is easy to do with PowerShell, but needs to be done on an ongoing basis because Exchange Online doesn’t have an organization or mailbox plan setting to assign the value to new mailboxes.
Sometimes delegate access for an Exchange Online calendar goes awry due to corrupted items in the mailbox. To help sort out problems, Microsoft has upgraded the Remove-MailboxFolderPermission cmdlet to do the work that used to be done by a multi-phase fix performed using the MFCMAPI or EWS editor utilities. The nice thing is that this method is quick, simple, and works well.