Hello, I'm not sure about your phone but have you downloaded the Rekordbox App onto the phone to use with the XDJ RX.
Is your hard drive formatted to Fat 32 at 4096 bit? The XDJ RX will only work with that type of formatting.
The load lock, when you update the firmware you still need to set the load lock option to on in utilities (press & hold the menu button).it's the first option.
Hope that's some help.
Thanks.