Issue
In a multi-WAN failover scenario under UniFi-OS (ex. UDM, UDM Pro, UDM SE), the InvisaGig configuration page is inaccessible via its defined local IP address (192.168.225.1, by default) when the IG is connected to a port configured as a secondary WAN interface.
Cause
By default, UniFi-OS will direct LAN client attempts to access the IP of any secondary WAN interfaces, out of the active primary WAN. This will fail as there is no available path from the active WAN port to the subnet of any secondary WAN.
Resolution
Create a Traffic Route which directs LAN clients to access secondary WAN IPs via their respective interface. In the screenshot example below, the IG is connected to WAN2 and has a local IP address of 192.168.155.1 (this IP is just an example when multiple IG units are being used; the default IG IP is 192.168.225.1):
