In some cases the user connects to a WiFi network that doesn't have internet access. The OS itself is able to display a warning in System Settings:
However, in my app NWPathMonitor
reports that the WiFi path is satisfied.
How could I detect that the internet access is not working while WiFi is connected?
I could try to connect to my own servers and report failures to the user, but that takes a long time to receive the timeout error. I cannot reduce the timeout, because maybe the user is on a very slow network and long loading time might be expected. But iOS can detect that there is not internet within a few seconds and display a warning, so I wonder how does Apple implement it in System Settings and if there is something I can implement in my app.