Could be, the product is actually just defective, right out of the box.
An item's compatibility may be limited, too; in that maybe you should
try running your OSX's Disk Utility on that external drive, and if need
be, reformat it to a more compatible Mac extended format. I'd never
take a new 'compatible' hard disk drive at face value, as being so...!
Disk Utility can do several things on a drive; low-level reformat where
it writes zeros over the contents, repair a drive, repair permissions
when an OSX volume is on the drive (as in a backup clone) & etc.
If you can get it erased, reformatted, etc, and it still won't work, check
with the supplier or retailer on getting a replacement under warranty.
Best of luck!
PS: be sure to dismount the drive correctly before unplugging it! You can
unmount it by using Eject under File in menubar, or drag disk icon to trash.