I have two iPhone 7 Plus phones. Both are connected to the same wifi as well as every device in my house. But my iPhone appears to choose the cellular connection for data. If I tell the app to only use wifi, or turn off cellular data, it works fine on wifi. But then its not usable when I leave my home. Simply opening up safari to google, it will say no internet on my phone but my wife goes right to it (cell connection is only 1 bar in my home). My instagram is crazy slow or won't connect, youtube videos will not play.