Track Appointments to CRM from shared Outlook calendar

Hi,

My users need to be able to track Appointment records from Outlook into CRM, on behalf of other people from shared calendars.

For example, the team PA has access to the manager's outlook calendar and creates appointments in their calendar. However, when the PA tries to track this into CRM we get this message:

"Tracked records will be synchronized when the primary owner's mailbox connects to CRM"

So I opened the manager's Outlook, clicked Sync and yet the appointment record was not created in CRM (all the manager's syncs are active)

Can anyone help?

Thanks.