good day. i recently purchased an r7000 nighthawk router about 2 months ago. it worked perfectly but now i am having some problems. the wifi would work perfectly with all my wireless devices but as soon as i connect my iphone to the network. its as if the whole network crashes. once the iphone is connected the internet cuts off. the wirelss signal will still be connected to all devices but no internet and as soon i turn off the wifi on my phone. the network instanly comes back up and the internet starts working again. sometimes i can use my iphone with the network, its not all the time this problem happens. please help