The inability to modify the Finance address object while being able to modify the Engineering address object suggests that the Finance object is being managed by a higher authority in the Security Fabric, likely the root FortiGate. When a FortiGate is part of a Security Fabric, address objects and other configurations may be managed centrally. This aligns with the Fortinet FortiGate documentation on Security Fabric and central management of address objects.

For improving reliability over a lossy IPSec tunnel, the fragmentation and fragmentation-mtu parameters should be configured. In scenarios where there might be issues with packet size or an unreliable network, setting the IPsec phase 1 to allow for fragmentation will enable large packets to be broken down, preventing them from being dropped due to size or poor network quality. The fragmentation-mtu specifies the size of the fragments. This is aligned with Fortinet's recommendations for handling IPsec VPN over networks with potential packet loss or size limitations.

From the OSPF interface command output, we can conclude that the port3 network has more than one OSPF router because the Neighbor Count is 2, indicating the presence of another OSPF router besides NGFW-1.
Additionally, we can deduce that the interfaces of the OSPF routers match the MTU value configured as 1500, which is necessary for OSPF neighbors to form adjacencies. The MTU mismatch would prevent OSPF from forming a neighbor relationship.
References:
* Fortinet FortiOS Handbook: OSPF Configuration

In an active-active load balancing scenario, when the primary FortiGate forwards the SYN packet to the secondary FortiGate, the destination MAC address would be the secondary's physical MAC on port1, as the packet is being sent over the network and the physical MAC is used for layer 2 transmissions.