XR500 with Sky Broadband

I have recently bought the Nighthawk Pro Gaming router, the XR500, in order to stabilise my internet connection when gaming and in preparation for when I get Sky Fibre installed next Sunday, an upgrade from Sky Broadband Max. However on setting up the XR500 with my current SkyBroadband Max, though I can get decent internet through a wired connection, the Wi-if to all my devices around the home is much weaker, and keeps dropping off. Can anybody help solve this issue? On setup, I connected the cable between the sky router and the Netgear XR500, and disabled the wireless access point on my SkyBroadband settings page. Do I have to do anything else? I am very new and inexperienced to this, so try and explain any help or suggestions in a very basic manner, and help guide me through each step. Any help much appreciated.