Dead pixels on both of my new Kobo clara's

I recently purchased a Kobo Clara BW. The first unit had three dead pixels (first photo), so I returned it. The replacement now has one dead pixel in the middle of the screen (second photo), where it's sometimes in the text so its less noticeable.

Is this common with the Kobo Clara BW? Should I return it again, or is it unlikely to get a flawless screen?

Any advice would be appreciated.

Thanks!