Opening a socket only works when 3G/4G is disabled?

Question

I want to do the following with my Android app:

• I have a connected object that emits a Wi-fi network (soft AP) so my app can communicate with it
• Connects to the local device on the network 192.168.0.1 which is emitting the Wi-fi

• I want to open a socket to communicate with this device

              socket = new Socket();
              socket.setSoTimeout(10000);
              socket.connect(new InetSocketAddress("192.168.0.1", 80), 5000);
  

This code works on most of my test devices, except on Nexus 6 (Android 7) I have the following cases

Case where it's not workking

• Phone connected to Wifi AND connected to 3G/4G

-> Socket can't open!

Case where it's working

• Phone connected to Wifi AND NOT connected to 3G/4F

--> Socket opens successfully!

What can I do programmatically to make it work in all cases?

Answer 1

I finally found the solution

final ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkRequest.Builder req = new NetworkRequest.Builder();
req.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);
cm.requestNetwork(req.build(), new ConnectivityManager.NetworkCallback() {
@Override
public void onAvailable(Network network) {
        cm.unregisterNetworkCallback(this);
        network.bindSocket(socket);
        socket.setSoTimeout(SOCKET_TIMEOUT);
        socket.connect(new InetSocketAddress(ip, port), CONNECTION_TIMEOUT);
    }
}
});