For what it's worth, I have seen several different bail (and other) parts used on the same model (Shimano) reel, including the revered Stradic. They are produced in different runs and sometimes the parts aren't quite as good. The "seam" you photographed doesn't look angled at all. I bet that's part of the problem. I would bet Shimano will replace yours with a slightly different bail part that will work fine. Let us know.