XPS 8900, how to turn off M.2 slot

I recently installed a MyDigitalSSD BPX 80mm 2280 M.2 PCIe 3.0 x4 NVMEe SSD on my XPS 8900. 

Since then I've been having trouble installing or booting Linux, any flavor. It may be a UEFI thing, but not sure yet.

I noticed that in the BIOS setup I can turn on an off individual SATA slots. I'd like to be able to do that for the M.2 PCIe slot with the SSD in it to see if that makes difference, but I couldn't find an on and off option like there is for SATA slots.

I know I could just remove the card, but I seemed to have been more than usually challenged getting it in there, so I'd like to avoid physically taking it out.

Anyone know if there is such an on/off option, in the BIOS setup or elsewhere?

Thanks.