Our iPhones (6s and 7) are often having trouble connecting to the wifi network. If I go to Settings -> Wifi on the phones, they will see the 2.4ghz network, but not the 5ghz network, which is what I've configured on them.
Turning off/on wifi or restarting the phones doesn't solve the problem. Eventually they seem to find the network and then connect. Occasionally, they will see the 5ghz network but not connect. If I manually select the 5ghz network, it will ask me for my password, which is odd because I haven't changed it recently.
My iPad and Mac don't seem to have this problem so I'm wondering if it is the iphones themselves, however I am posting here in case anyone knows of a known issue with the router itself.