M.2 not work?

[XxWOODSIExX]

I have installed in my pc two Sabrent rocket 4.0s and one sabrent 8tb drive as well. For some reason I can only get two out of three to show up and they are all seated correctly. 

[TylerD321]

Move them around into different sockets. Entirely possible that you either didn't seat it correctly and thought you did, or one of them are just bad.

[Robchil]

check your mainboard manual for m.2 config.. sometimes one slot isn't working in certain configurations.