Is this hard drive new?

I started testing the disks by reading from and writing to a few points in the disk to find obvious faults. When reading data from a fresh HDD, I had found that most bytes of the disks were initialized with zeros,

When I buy a new, good quality hard drive, there are no errors on the drive. That has been true for some years.

A new drive needs to be initialized as a drive (still blank) and then formatted. No errors at that point for me.

So I suggest the drive is either not new, or has been reconditioned/remanufactured (new controller card and test) to sell as "new". Data may have been left over from such a drive.

I suggest returning it and purchasing another drive.