First of all, make sure you have data available to RUT240 itself. Go to CLI, log in with root and your password, and try to ping 18.104.22.168. If ping doesn't pass - you probably need to set-up your mobile connection correctly. (Custom APN in Network > Mobile page).
If your ping passed through RUT240, then make sure you didn't change any particular Wireless settings that could've caused this issue (to be sure you didn't it's best if your factory reset your router without keeping the settings).