Hi,Welcome to Just Answer, My name is XXXXX XXXXX forward to helping you today.
inside the freezer in the back middle there is a dial for air flow have you adjusted that? # XXXXX on this diagram.
I don't have anything that will adjust airflow in my freezer .The only thing in there is a box in the back middle that says freezer temp which is set on three which seems to be giving me a temp of zero in there which is good.
The airvents in the back -top of fridge are just open vents with no controls.