Network issues, such as an iPhone's sporadic Internet connection, can cause network-related and server-based apps, such as Facebook, to crash. Because the app must communicate with the server in real-time based on user inputs, it is likely to crash if it is unable to establish a steady connection with the server. Toggling the Wi-Fi switch off and on again might assist address small difficulties with your Wi-Fi internet.
Navigate to the Settings-> Wi-Fi menu to do so. Then, quickly hit the Wi-Fi switch to turn the function off, then tap it again to turn Wi-Fi back on.
This can assist in the resolution of small network issues that may have led network programs to go rogue.
