Maybe leigh76, will post his results. If second M.2 ssd is not seen/recognized then it probably is an asus issue. Board or software?
Thanks for getting back to me, I think I now have the answer! It appears that the Asus Ranger ONLY supports M.2 PCIe and not M.2 SATA and it is an M.2 SATA device that I have (SM2280S3/120G). Seems odd though as all of the other manufacturers MSI , Gigabyte and ASRock support both standards! Also the Asus motherboard manual is very unclear on this, with just a small section near the front of the manual giving away its lack of M.2 SATA support. Hope this helps some others... ;-)