DIAGNOSIS The magnetic door gasket isn't making full contact with the metal frame. This could be due to the door being misaligned, the gasket being dirty, or the unit not being level.
FIX Let's get it sealing. 1) Check and adjust the leveling feet again. An unlevel unit can twist the cabinet, pulling the door away from the seal. 2) Clean the rubber magnetic gasket on the door and the matching metal frame with a damp cloth. A tiny piece of debris can break the seal. 3) Check the door hinges. They might allow for slight adjustment. See if the door can be gently lifted or shifted to sit more squarely in the opening when closed. 4) Perform the dollar bill test: close the door on a dollar bill. You should feel significant resistance when you pull it out. If it slides easily, the seal is weak at that spot.
IF THAT DIDN'T WORK If the gasket itself is deformed, kinked, or has lost its magnetism, it will need to be replaced. You'd have to contact the manufacturer for a replacement gasket kit, which involves carefully peeling off the old one and pressing the new one into the channel.
HEADS UP A bad seal makes the compressor run constantly to try and keep up, which will drastically shorten its life and skyrocket your energy bill. It's worth taking the time to fix this properly.