As long as the bracket is torqued correctly, and the plates are flat against the frame, and the brackets are the proper distance from the coupler, this shouldn't happen.
I bent some brackets on my hitch from torquing it wrong (if you bend them, they'll never be right again). When I went to order replacement parts, I discovered that these spring bar hangers and brackets have been re-designed. I can't tell from the pics whether you have the new design or the old one. I can tell you that the new design is FAR superior and solves all sorts of problems.
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!