Steps: Adding HA devices to Panorama

1. Enable Config Sync (untick on both)(commit).
2. Specify Panorama Server on HA Firewalls and Enable Policy, Objects and Templates options (commit).
3. Add Firewalls as Manages devices in Panorama using serial numbers (Tick Group HA Peers) (commit Panorama).
4. Import Device configuration to Panorama (Post Rule/Leave ticked) (Primary)
5. Import Device configuration to Panorama (Post Rule/Leave ticked) (Secondary)
6. Commit (Panorama) (Creates Device Groups and Templates for both).
7. Remove Secondary Template and Device Group and Add both to the Primary Device Group and Template.
8. Export Configuration (Push and commit) Device Group config to Secondary only and Make the Primary suspended for Secondary to takeover.
9. Export Configuration (Push and commit) Device Group config to Primary now and Failback to the Primary.
(Both Should be showing In Sync under Managed Devices under Device Group and Templates)