Apple changed some things regarding WiFi with iOS 13. If you want to use CNCopyCurrentNetworkInfo your app needs to have one of the following
I have a similar issue in my app. I have submitted a feedback form to Apple and got a response stating:
Potential fix identified - For a future OS update
So hopefully, this will be resolved before the final release (not in iOS 13 Beta 4 though).
For a workaround, you can set joinOnce = false in your NEHotspotConfiguration. In my app, it allowed me to access CNCopySupportedInterfaces, but required me to remove configuration every time my app was closed.
Hope it helps!
Edit:
It seems that in iOS 13 beta 5 issue no longer persists. In my application, I can access CNCopyCurrentNetworkInfo again (thus confirming the Wi-Fi has been connected), no matter if NEHotspotConfiguration.joinOnce flag is set to true or false.