Since the introduction of Palo Alto Networks Firewall enforcer, reordering of resource policies is available only for SRX enforcer not for PAN/Checkpoint.
In the Resource access policy page, you will see a drop-down to select enforcers, in that if you select any SRX enforcer, you will immediately see the Save changes button.

The reason why Save changes button is removed for any other firewall except SRX is, There is a possibility of resource policies being managed by Pulse server and policies can be Firewall managed, if we provide the option to re-order the policies in the PPS, this will delete and create policies in a new order in Palo Alto Firewall. This will impact the order of resource policies in the Firewall managed policies. This may lead to unexpected access blockage for the users. This is an expected behavior.
