There are users in Active Directory that should not be synced to CloudSOC.
In the sync filter, include !(userAccountControl:1.2.840.113556.1.4.803:=514). This is the default attribute that identifies inactive AD Users. The exclamation mark filters out inactive users
Filter Example:
(&(objectclass=user)(objectCategory=user)!(userAccountControl:1.2.840.113556.1.4.803:=514))