Yes it is.is your memory in the same brand and same specs??
Its only two slots, my mobo is Asrock AB350m-hdv, on the asrock site it says support dual channel memory.Hmm could be a bug with cpuz. What motherboard is it, does it have 4 dimm slots?
Bios is saying slots a1 and b1, if you do have 4 slots try a2 and b2 which are the primary slots. 2nd and 4th slots from cpu.