Make sure your IFLY app has the ADS-B setting to "Auto-Detect". I use an old Samsung tablet and a Pixel 3a and setting it to "Xplane" never worked properly for me.
In Xplane (I'm using XP11), in the network settings, check to box labled "Broadcast to all mapping apps on the network."
Make sure your XP PC and the phone/tablet are connected to the same network and you should be in business.