Hi @chambersj ,
Setting IP passthrough on RV50/55 will assign WAN IP directly to your host(It is Fortinet in your case ). Please try below the configuration
-Enable Passthrough
- Make sure Port forwarding/DMZ is disabled
Then, the connected device gets WAN IP of the GW
Please share if you have any questions. Help us tick “Solution” under my response if it is useful. It might be beneficial to someone getting same concern
Thanks