Some mobile phones do not recognise modified network names. First try restarting phone as it does often help. The solution is reset the modem by pressing reset button for several seconds with fx paper clip. If you reset the modem it will also change default wifi settings. The reset button is behind the battery cover on the modem back. Restart. You should see the new network name and password on the modem screen when power button/WPS/menu button is pressed.
