I found a small but critical BUG.
If GCSM synchronizes data while in Outlook there is a pending appointment (NOT YET CONFIRMED), an appointment is created in Google as "AVAILABLE".
But when in Outlook you confirm the appointment and it becomes BUSY, in Google the flag does not update and remains "AVAILABLE".
As a result, when other people access the shared Google calendar, they see that the person is AVAILABLE, so they arrange meetings in conflict with the existing ones.
In the attached picture you can see: