MAX-BR1 IP Passthrough & fowarding with Peplink MAX Adapter 5G

Is there an option for IP Passthrough and forwarding via the WAN USB port?

Under the USB WAN, If I try to disable NAT and select IP forwarding it always reverts back to NAT after saving. I do not see any option for IP Passthrough.

Want to set the MAX adapter as Priority-1 and the built-in cellular priority-2 (backup).

IP forwarding & passthrough work as expected through the cellular WAN.

Greg