Sophos RED 10 unable to communicate with XG firewall

Hello,

I configure Sophos 10 for our remote office.

I configured the device in our main office, by doing following:

I connected it to our modem with a DHCP IP, and configured the device I see it in the device management, and I have the unlock code. I connect a laptop in the RED device and it was working fine

After that, I disconnected the device, and sent it to our remote office. The remote office has a router, so I connected the Sophos to the WAN port. And it doesn't work.

The sequence led is following:

 

Device is powered on

Power-LED and WAN led are steady - about 45 seconds later System LED turns on - 10 seconds later Router LED turns on - then Tunnel LED is on, after a few seconds the LEDs of System, router, internet and tunnel are off and then the are on again.

Has anyone experienced the same?