Having problem with Bosch freezer (((Help please)))

I have a Bosch fridge frrezer which I have been experiencing problems for a while.

It will not reach -24 -26 max temp. I changed the thermosta and then the pcb. An engineer said that when you cange the pcb the machine needs to be reset so i did that too.

What is confusing is now the temp display is not flashing and showing -24 but the ice cubes are not frozen. Only the top layer of the ice cubes are frozen which hints to me that the frrezer is displaying the wrong temp.

I would appreciate any advice orassistance.

Thank you