Kingston HyperX Fury on ASrock z97 Extreme4

Hi. I have bought 2x8GB Kingston HyperX Fury 1866 Mhz memory, and first time have installed it on bank 2 and 4 but the mobo is showing error 55 (memory not installed) . After that I have installed it in bank 2 & 3 and it's working in dual channel mode. My question is how is that possible?? cause as far as I know, dual channel should only be working when memory is installed in banks 1 & 3 or 2 & 4??

What motherboard do u have?

The motherboard is ASrock Z97 Extreme4