Two of my Portable SSD have the same problem

Hello.
Before writing, I applogy for my bad english first.

I’ve bought two of WD SSD from amazon.com

‘WD 512GB My Passport SSD Portable Storage - USB 3.1 - Black-Gray - WDBK3E5120PSL-WESN’

They seemed fine at first,

but everytime when i try to test these SSD with HD Tune, An Error occured.
It seemed They’d been disconnected.
Both are the same.

They both just stop in the middle of test. Like this.

Before HD Tune test, They both pass WD SMART test
But after Hd Tune test, They both fail WD SMART test
It seems they are disconnected everytime i test with bad sector(Cell) checking Utilities

I tried to test these SSD with other utilities, and the results were the same.
And also I tested with My desktop, laptop.

I wonder Why is this happening?
Do i need to receive a replacement for them?