Apple TV 3 now invisible to iPhone so can’t airplay

iphone can’t see Apple TV after changing WiFi networks. Have followed all the recommendations… updated the apple tv & phone to latest version, turned off router, phone & Apple TV and restarted, made sure all on same WiFi network. Still can’t see Apple TV. Even went back to old WiFi network selection and still can’t see Apple TV to air play. Any advice on the fix?