ARC-XC155AX no internet if in pass thru mode

[Trapper3200]

Gateway works normally if not in pass thru mode and used stand alone.  If pass thru mode is enabled and connected via LAN2 to the router (Asus RTAX86), the router shows internet connection and reports an ip address, but all devices report no connection. 

Router functions fine with cable modem.

Ideas?

[scott31339 · Accepted solution]

I have the ARC instead, but I did use my laptop in LAN1 to get the IP passthrough set up, and then plugged into LAN2 to verify connectivity. Once I did such, I plugged into my ASUS router (RT-AX88U) and restarted both devices, and all was good.