Using Tailscale on my Beryl AX

I have set up tailscale and bound its connection. I want to use an Amazon FireStick connected to my MT3000 and the Tailscale network connected to the exit mode on my Synology NAS. However whatever I seem to do I can’t hide the device behind the Tailscale VPN.

I have enabled Allow remote access to WAN and LAN and approved subnet ranges in the Edit Route Settings of the Tailscale set up.

Any help welcome