Question edited for clarity.
Question moved from Cars and Trucks!!
This has all the hallmarks of a fridge that may be overloaded with weight, on an uneven floor with misaligned levelling feet.
Cut a piece of 1" marine plywood 1" bigger than the width and depth. Empty the freezer and put it on the plywood. Level the feet using a spirit level left to right and a fore and aft. Make sure it doesn't rock. Loosen the door hinges and centre the door. Fill the freezer back up.
My advice is never to use the self cleaning feature. Each time you use it you are a little closer to breaking something, elements, fans, door latches and one poor man who had a burned / melted control board which was obsolete so he had to purchase a new range. We see it here all the time. It is a great way to sell spare parts. 800 to 1000'F is just too severe for the parts.
why not call for service
they have tools to fix things you do not have
and more important skills.
why not contact maker Frigidaire dot com and ask for screws. and or prime help in your unstated town. or country.