Stove top thermal protection failing

I apologize in advance if I do not have the right terms, hopefully you will understand what I mean to ask.

So, we bought a Samsung brand stove top (NA75J3030AS), we have been using it for the last 6 months. Unfortunately for us we kept it in a box for some time so there´s no warranty as of now.

There´s a couple of the thermal protection devices which do not operate properly, meaning that once you stop pushing the knob gas will stop flowing.

I understand there´s a couple of different...

Stove top thermal protection failing