If you open and close it then try to open it again with in a short time the frost-free may still be active.
Frost free sucks all the air out of the freezer to prevent all the icing.
I find pulling back the insulation for a second releasing the pressure makes it easier to open, or waiting 10 minutes for the pressure to equalize.
Please let me knwo how that goes, it could also be a clogged vent making this problem seem worse.
If you still have trouble you can use Baby powder all the way around the door seal. This should help quite a bit . But It sounds like you may need to defrost this frost free unit as sometimes ice formation behind the rear wall will cause this problem. To do this properly you need to empty the fridge and freezer, and then defrost it for 24 hours with the doors OPEN.
This should help a great deal with this issue;-)
In any case, I will stick with you until this is complete.
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