I'd like to join to this topic. I have the same issue. Recently I've bought 512GB SSD replacement for Mac Book Air A1466. I bought it because oryginal 128GB SSD capacity is far not enough for me. Unfortunatelly Mac was unable to recognize the device and I returned it to the seller, Then I've bought another one from other place, marked as being from oryginal Mac Book Air. This item also remained undetected by Apple Mac Book Disk Utility. Yes, I ticked "show ALL devides" option from View menu.
Finally I was forced to return to my oryginal 128GB too small SSD.
Any ideas?