BekoCF5015AP fridge freezer

BekoCF5015AP fridge freezer. I bought this particular model as it lives in an outbuilding and is supposed to be designed for this purpose as my previous Beko fridge freezer was turning itself off when it was really cold in the winter.
It’s only a couple of years old and it’s freezing veg in the fridge. Ice is forming on the back wall of the fridge and around the drain hole. Have read stuff on this forum, (but about a different model), that it’s the evaporator sensor that’s causing the problem, it also seems to be called a thermistor. There are various posts that describe cutting away the insulation and replacing this part. Would the same procedure be okay for my model fridge freezer? Also what is the part number of the part required? Any info most welcome. Thanks. PS It’s also been suggested that defrosting the fridge freezer might cure the problem ????