When User has Editor permission on shared calendar. Occasionally user can track an appointment but when user sets the Regarding the activity does not sync. It says " This meeting will be tracked after it is saved or sent." Many times when user tries to track it says "You can't track an appointment that was created by another User." this is an trending issues and it would be fixed with 8.1. Even we are still able to repro the issue on 8.1 org cannot track and sync items on a shared calendar.