iPhone 5s screen juddering

[slayer1551]

I recently noticed that when I was scrolling and kept my finger on the screen that it would start juddering up and down but then sometimes it would return back to normal.

However after some testing I just figured out that whenever the charger is plugged in it start juddering again and stops doing it immediately after unplugging the charger. I'm just wondering if its just my phone that has an issue or if its a common fault, has anyone else experienced this ?

Here is a video of it happening