Unplug it from the phone socket, wait about three minutes, then plug it back in again and wait for the light to go blue again. That should give you a different public IP address, just in case you are connected to a stale session.
Is anything connected using an Ethernet cable, and does it work? Is it just wireless devices that are affected?
Might be worth trying a factory re-boot. There is usually a small button that has to be pressed with a paperclip for 10 seconds.