Devices keep dropping from wifi network - Nighthawk X6 AC2200 EX7700

Set up both using WPS and manual method my new Nighthawk X6 AC2200 EX7700. Connected to Virgin Hub 3 modem / router. Followed everything to the letter. Also updated firmware via the App. Our devices keep dropping from the network even if they are right by the extender! We have a couple of ipads, couple of iphones, a macbook and a laptop. Certainly a lot less than the advertised 40 devices the extender claims to handle! Absolutely terrible product. Ipads keeps saying "incorrect password" when trying to connect to the extender wifi. Will be sending back at this rate.