CF-19 MK6, second/top ram slot non-functional

I recently purchased a 16GB DDR3L memory kit by Crucial, upon installing both sticks, my CF-19 booted fine, but I discovered it was only recognizing one stick (8GB) of memory.

I used the 4GB ram stick that came with my toughbook plus the known working 8GB stick and the bios recognizes 12 GB of RAM, I suspect it might be a bad ram stick.


Is there any setting I'm neglecting to change? Or maybe something else?