Microsoft Office, Exchange, Calendar, Snooze issue, Resending Invitation
I can't confirm that this is a common behavior in Mac Outlook or Calendar. It's working as expected.


  Why is this happening?


It's a incompatibility issue with your Exchange Server. e.g. a outdated MS Exchange server version. Somehow your Mac Outlook changes are ignored or not being synced. What Exchange Server version do you use? Also make sure that you are running the latest Mac Outlook Version. 

The best way is to get in touch with your ISP or Server Administrator, so he/she could take a look at the debug logfiles.