When a security rule is configured as Intrazone, the destination zone field cannot be changed. This is because an intrazone rule applies to traffic that originates and terminates in the same zone. The destination zone is automatically set to the same value as the source zone and cannot be modified1. An intrazone rule allows you to control and inspect traffic within a zone, such as applying security profiles or logging options2. Reference: What are Universal, Intrazone and Interzone Rules?, Security Policy, Updated Certifications for PAN-OS 10.1, Palo Alto Networks Certified Network Security Administrator (PAN-OS 10.0) or [Palo Alto Networks Certified Network Security Administrator (PAN-OS 10.0)].