Liebherr fridge sounds, cooling and LCD problem

Hi
I have a 2 year old Liebherr refrigerator, model CBN3857, with Biofresh and nofrost.

It worked perfectly until the last month, when it started to make strange sounds. It's happening when the fan turns on/off and sometimes in between when the fridge is working. The sound is like shooting, or something like banging with a stick, or plastics crackle. Sometimes the sound is very loud, sometimes not so loud...

At the same time I've noticed that the temperature in the Biofresh drawyer seems to be too cold, as the vegetables started to freeze. The LCD screen on the front door showed the freezer temperature -18, and the fridge +5.

Few days later, the LCD screen stopped working at all, but the temperature seems to stay the same, and the sounds remain.

Does anyone have any clue if these all failures are related together? Could defrosting/switching off help with any of this (I can't see any frost in the fridge or in the freezer, but maybe it's somewhere inside?)

Thank you.
Brigita