I don't know. It could be a bug in the TV. That is why I said you may have to run a cable from your router to the TV to let it do an update before WIFI will work correctly.
I have no magic insight into your TV. You can do basic WIFI troubleshooting... Do you have SSID broadcast enabled on the router. Do you have MAC filtering enabled on the router? Do you have WPA2 encryption enabled?
If you don't know the answers to these questions, you may need to get someone with more network/computer experience to help you hands-on.