Defrost Grid Lines
 

I have a 2015 NX 200t and it appears that one of the defrost grid lines is not defrosting. All the other lines are clearing the frost.
Does anyone have this issue? I'm still under warranty so I'll most likely take it to the dealer. But before I do that, is there anything I can check/inspect by myself first?
I didn't install any aftermarket tinting, just the tint that came with the car.

I had a Rav4 that that happened to. I imagine it's faulty heating element, probably a short/disconnect in the conductors. Should be covered by the warranty.

Simple google searches are helping me immensely right now. and this is just adding to it. my rear defroster isnt working either and found the burnt plug. gonna go junk yard hopping and hope for the best.

In case #1, it is damaged heating grid line. They are very easy fix DIY.
In case #2 - burnt plug? Which plug, where? Wh0pp?