Why is there a horizontal thin line?

Hey guys,

So I was connected to the PS4 through the HDMI. Randomly, I got this thin grey-ish line a bit lower than the middle of my screen and I can't figure out what the problem is, given the fact that the TV is less than 2 months old.

The model is a UE40NU7122K

The Type No is UE40NU7122

I tried:

1) turning the TV off and on again

2) changing the source from HDMI to TV

3) unplugging the power cord

4) changing some image settings

If anyone can help, I would be grateful