Issues with my passport pro

Hi everyone. I have got a My Passport Pro, which is 4 TB. It is a 2 of 2 TB hard drive. After I spoke to the Apple specialists, they advised me to get in touch with WD regarding this issue. What they “Apple specialists” believe is this, the hard drive copies the same date on the both hard drive at the same time. Off course runs another issue for me by taking more space on the hard drive.

I would kindly appreciate anyone’s help and support.

Kind regards

Darya Said