I have a strange issue with my Extender.

My router is downstairs and it gives a good signal to the upstairs hallway, but the signal in the bedrooms is too low. I put the extender in the upstairs hallway, it receives good signal from the router and it gives 3 blue lights indicating that it is in good range and the 2.4 and 5Ghz wifi is connecting.

I can connect all my devices and everything works on either 2.4 or 5 networks.

Everything works fine for a while, but after some time one of my devices; ipad, iphone, laptop will get no internet connection. There is a strong signal and it's connected, but I get a no internet message. I can reboot the device but it still will not work. I can usually connect to the other Ghz band and it will work for a while. During this time my other devices usually still work uninterrupted, but sometimes it hit more than 1 device at the same time. 

I can fix this 100% of the time by rebooting the wifi extender.

IP address conflicts? Maybe because I have the same SSID coming from the router and the extender it gets confused? Any ideas?