Yeah I am pretty sure they didnt used to years ago put manufacturer's name in place of seller on product page. Kind of shady.
Sold by samsung instead of sold by del trotter.
The first warning sign was weird behaviour and apps reported hdd's had no NCQ support yet it was in the hdd spec sheets.
Someone then suggested I check the serial on the warranty page, which reported it was invalid, I knew then was fake.
Also I believe I lost data, seemed similar to how people lose data on fake sdcards. As I copied data to the drives, then realised the situation had to copy back and I lost some of it.