Can't seem to get your Raspberry Pi 3 (& Newer) Wifi working with your iPhone?
Don't worry! The fix is easy.
The default wifi name or (SSID) of the iPhone hotspot is set by the name of the iPhone for example, "David's iPhone". The quick solution involves changing the iPhones name in the General settings tab to a name which does not contain any special characters. It is best to choose a single word for the phone name, save, and enable the hotspot again. The Raspberry pi should detect the wifi connect and connect successfully.