Just got my new GE

Question

Just got my new GE Cafe microwave. Set it on the table, plugged it in and it worked fine. Hung it on the brackets, plugged it in and it does not work. I do have power to the outlet. I have tested it repeatly. When I remove the microwave from the wall and set it back on the table it works. I am an Electrician so I know if I have power or not.