The configuration shows that VRRP (Virtual Router Redundancy Protocol) is enabled and both FortiGates have the vrrp-virtual-mac enable command, meaning they share the same MAC address. The primary FortiGate uses its physical MAC address as indicated by the set type physical command. The priority value determines which FortiGate is the primary virtual router, and in this case, FortiGate-A has a higher priority than FortiGate-B, so it is the primary by default. The IP address 10.1.5.254 is the virtual IP address of the VRRP group, not the default gateway of the internal network. Reference: You can find more information about VRRP configuration and troubleshooting in the following Fortinet Enterprise Firewall 7.2 documents:
VRRP
Technical Tip: FortiGate VRRP configuration and debug
Configuration Example: How to configure VRRP between a FortiGate and a Cisco router