MacBook Pro or iPhone 6 won't connect to 5GHZ Asus Router

I have an ASUS RT-N65U using a custom firmware (3.0.3.7-075) from http://ift.tt/1meAkbf

So I can change SSID options for 2.5GHZ and 5GHZ but I can't connect to the 5GHZ variant. In my Mac says connection timeout. On my iPhone it immediately shows "can't connect".

I'm next to the router, because I'm testing so I don't know what else to do. I can change MTU, Channels, etc... Any suggestions?