Hello everyone! This is my first post so please be nice to the noob. 
I recently replace my router with Nighthawk R7960P, my first netgear router, and I am struggling with getting access to the network through and AP that is wired into the Nighthawk. The AP is an old Apple Airport Express that use to work just fine with my previous router. Now I still have internet access through the AP but I cannot see any devices on the network. So if I connect to the AP I cannot print to the network printer connected directly to the Nighthawk. Also if my chromecast connects through the AP I cannot cast from device on the Nighthawk. But you can see the chromecast if it connect directly to the router. I guess there should be a setting in the router GUI to allow devices connected through the AP network access, but I am not very familiar with the interface so I can't find it. Can someone please help me out?

I recently replace my router with Nighthawk R7960P, my first netgear router, and I am struggling with getting access to the network through and AP that is wired into the Nighthawk. The AP is an old Apple Airport Express that use to work just fine with my previous router. Now I still have internet access through the AP but I cannot see any devices on the network. So if I connect to the AP I cannot print to the network printer connected directly to the Nighthawk. Also if my chromecast connects through the AP I cannot cast from device on the Nighthawk. But you can see the chromecast if it connect directly to the router. I guess there should be a setting in the router GUI to allow devices connected through the AP network access, but I am not very familiar with the interface so I can't find it. Can someone please help me out?