Review on SanDisk 64GB (Two Pack) Extreme Pro Memory Card (SDSDXXY-064G-GN4IN) SDXC 4K V30 UHS-I With Everything But Stromboli (TM) Combo Reader by John Bones

I don't know if it's a card or a reader but I used it in my camera and then inserted the card into the reader and imported light space . Everything went well. But when I transferred some files to the card and plugged it into another laptop, I was told that the card needs to be formatted before use. I tried again on the first laptop - same thing. Just tried a card into the built in card reader in another laptop - same thing. Now I don't trust this card or reader at all. Edit: I did a read/write test and got horrible numbers. 16 Mbps on a laptop; 20mb/s on another. Must be fake cards.