I agree with Darenh's comment, I have a 17 plate Kadjar with the vinyl half and half seats, and while they look ok, the vinyl on the sides is incredibly thin, and mine has just split on the driver’s side nearest the door. I thought at first a stud or similar from jeans or trousers might have caught it as I got in/out, but after checking they are too high up and smooth to have been the likely cause. Having seen how wafer thin the vinyl is, it was clearly a matter of when, not if, it was going to split..!!.
This is a real pain, I would rather an alternator or other easily swapped out part go than trim which is so noticeable come trade in time and usually very expensive to repair, and although mine is still under Renault warranty, I'm sure the they'll refuse any action under the "wear and tear" get out. I'll have to tape it over for now to stop it spreading, and see if an upholsterer can do anything.
Although I have had this happen to a seat before, that was on a 11 year old car, not a 4 year old one, seems its not just anything/everything electrical a nightmare on modern Renaults - but poor trim materials too.
I wonder if any other owners of this seat type have experienced the same issue and if so, how they fixed it?