Go into Wi-Fi – Settings – Advanced and make a note of your device MAC address, then make sure that it is allowed access in the router’s MAC filter.Make sure the applications and software on the device are up to date.Make sure the router firmware is up to date.Forget the Wi-Fi connection by going to Settings – Wi-Fi and long tapping the connection you want, then selecting “Forget”.Use the Wi-Fi Analyzer to check how crowded your channel is, and switch to a better option.Go to Settings – Power saving and ensure that this option is turned off.Turn the device and the router off for at least ten seconds, then turn them back and retry the connection.Change it from the default Automatic selection to 2.4 GHz only, and this seems to fix the problem for most users. Go into the Advanced settings in the Wi-Fi menu of the phone, and look for Wi-Fi Frequency Band. This seems to be a very common issue, specifically with wireless routers that support both the 2.4 GHz and 5 GHz bands.
