[Gamepad] Strange 'brightness lines' on my gamepad

I'll explain further.

I noticed this issue about 2 weeks ago, when I was playing Mario3DWorld. After clearing a stage, you get to a red background screen... where I could see 1px width lines which had a slight difference in their brightness levels between them.

I'm also attaching a picture, because I never heard of this issue.
Pay attention to the small lines in the gray background, behind 'BAYONETTA'. Remember that the lines are 1px width, but there are so many...

The lines are all over the pad and it's driving me insane. OCD pretty much but it can't be helped.

Any suggestions?

(the gamepad works perfectly... but these lines are annoying).