Norcold 4 door fridge/freezer door hard to open

I tried a heavy business card in the right door seal. No difference when trying to open the left door. Also folded over the card to double the thickness - no difference. I don't think it's vacuum holding the door closed. Feels mechanical. I inspected the top and bottom of the flap and the pieces on the fridge and there doesn't seem to be any scrapes or abrasion. Must be something else. Maybe I'll try putting a washer in the hinge to raise the door a bit??