In fairness, it has behaved this way since I got it 3 or 4 years ago. Time to splurge.Phil if the fridge is icing up in places and not cooling properly then there is an issue with the gas in the system and the compressor stays on longer to try and cool the fridge down and satisfy the internal stat. As it can’t cool the fridge properly due to lack of gas it causes “cold spots” and these freeze up. I used to see it a lot in air conditioning units as they work on the same principal where a lack of gas causes the unit to ice up.
These days it’s not really cost effective to get a fridge man out to regas the system and if it’s an older fridge running on r407c you won’t even get it anymore.
get a money box and start saving as the end is near.