Redundancy groups are defined at router level for the interfaces to be in HA. When trying to configure a new network interface on that wan interface which is in HA, conductor will throw below error. The error shows up when validating the config.

“The 'type' of element 'network-interface' must be set to 'external' for redundant interfaces”

SSR software explicitly prohibits GRE tunnels on interfaces using shared physical addresses (redundancy groups) by design. To achieve the desired configuration, the user is required to use VRRP for high availability instead of redundancy groups.