Things to look for:
Check the door frame bottom for any signs of rubbing from the bottom of
the shelf on the door. This can happen sometimes at the lower shelf, by
loading it to kingdom come with lots heavy items.
Check for alignment, and how the door itself closes, and meets the body
of the fridge. The soor could've sagged a bit over time, and one, or
both hinges may need to be loosened, the door lifted, and the hinges
Again, look for evidence of rubbing.
How does the door open, and close? Does it feel smooth, effortless when
swinging back, and forth? Try a drop, or two of some good lube oil at
the hinge pins, and see if this helps?