Computers not connecting, but ROKU is still connected

I have a Nighthawk RAX30

I have two computers, they connect fine, until i shut them off, use them in a different location wifi etc...  I have to reset the router nearly every time i try to get back on.

I have a ROKU, and it stays connected.  I try using the app, and it cannot find the router until i shut it down, and reboot.

I have done all the updates.

solutions?

thanks