Liebherr larder fridge not working in normal mode

Question

I have 8 year old free standing larder fridge with no ice compt. in past fee days fridge has increased in temperature despiter placing dial to max. Super cool still works and will cool the fridge down nicely, but will cut off when its supposed to do. However, eventually the temp rises and one has to revert to super cool function. If it ws compressor the super cool, would not function so either the thermostat is u/s or something else could be wrong. Please advise - thank you.