I have an airport extreme base unit and utility can not find it

I have a 5th gen airport extreme router which works just fine with I plug in an ethernet cord to it … however when I want to use anything else (iPad, iPhone) my router is not showing up in any of the airport utility scans … my wife said yesterday it popped up a question and she either accepted it or said yes and since that point it has not shown up at all … on mac, pcs, iPad, iPhones nothing … I've even tried to do a hard factory restart of the base station and it still hasn't worked ... any ideas?