Nighthawk x4s ex7500 all devices have internet but no wifi

[Alfweasel]

All devices except two in my home have internet but no WiFi. We bought extender to get better WiFi, we have better WiFi for device that needed it and none for almost all other devices. How do we fix?

[plemans]

I guess I'm curious how you can have internet but no wifi. 

Maybe a little better explanation of what the issue might help clarify. 

Also, what firmware is on the ex7500?

And what router is the ex7500 connected to