I bought a Asgard (seems operates from HongKong) 2TB NVME PCIe M.2 SSD that I installed into mackbook pro 15in mid 2015 with sintech adapter for conversion to MacBook AHCI controller. The disk utility does not show this SSD. Later I installed in same way another Sabrent SSD 2TB it worked fine.
What might have gone wrong in the fist SSD. Could that SSD itself faulty or incompatible? any fixes available?