This article covers how to address an appointment showing duplicate blocks on the Staff Calendar.
The user must have Create and Edit permissions on the Appointment object, in order to fix the duplicate.
Duplicate Appointments On Staff Calendar
If you notice that only one (1) appointment is scheduled but there are two (2) calendar blocks showing on the Staff Calendar, the likely cause is the appointment has been assigned to the Sales Rep twice (both Sales Rep 1 and Sales Rep 2 fields are populated with the same Staff member).
Click on the calendar block to open the Appointment record in a new window.
Click Edit on the Appointment.
Remove the Staff member's name from the Sales Rep 2 field. Sales Rep 2 should be left blank. Click Save at the top to continue.
Return to the Staff Calendar, you should now see only one calendar block for the Appointment.
NOTE: When Saving an Appointment, the system will display a pop-up message (see screen shot below), warning you if you have entered the same Staff member in both Sales Rep 1 and Sales Rep 2 fields. If you click OK, the system will display two (2) Calendar blocks for one (1) Appointment.
Best Practice: Here, you should click Cancel and remove the duplicated Sales Rep from the Sales Rep 2 Field.