WiFi button locked in off position

Done reset all settings. Turned WiFi router off and back on. Hard reset, nothing works. The problem occurred in March but with lockdown couldn’t do anything. Then a couple of days ago he plugged it back in and charged it....it looked good as was able to connect to WiFi. Then he updated the latest iOS software (as you are encouraged to do) and straight away back to square one. Very frustrating

Done that but it’s still greyed out