Amana GC2224GEKB Fridge/Freezer temperature issues

Hi – can someone please help with this problem. Amana GC2224GEKB side by side American Fridge Freezer stopped working whilst we were away (great!). We wanted to try and fix it so googled and found out how to run various checks including capacitor and relay which were both ok, came to conclusion it must be issue with PCB so ordered replacement. New board fitted but it wouldnt accept code 28 so we used code 01 and everything started working and seemed fine, freezer reached -18 very quickly but fridge wouldnt go below +8, left it to settle for 24 hrs but no good. Spoke to company who supplied board and they sent another PCB. Fitted the 2nd one, code 28 wouldnt work on this one either, neither would code 01 so had to use code 05. Again freezer worked fine but had same problem with temp in Fridge not going below +8. Replaced the thermistor, followed reset procedure and then set both freezer and fridge to setting 4 and waited, freezer got cold quickly but only to -15 and fridge to warm around +6 to +7’ish. Over the course of last few days i have changed the settings slowly one setting at a time on both sides trying to correct temps but it just wont play ball. Freezer gets as cold as -16 to -24 and fridge anywhere from +1 to +7 depending on settings and just wont balance – Can anyone advise on this please