If the 2016's and 2018's fly tail right, indicating overspined, then it doesn't make sense that a 2113 would work better. Maybe you ought to give 1916's a try, as the previous poster suggested.
One other thing occured to me: how are you holding the bow for your bare shaft testing? I bare shaft test with the bow in a vertical position, so I don't have to make allowances for my cant in determining whether the arrow is flying nock high, nock left, etc. Others hold their bows in their normal canted position, but adjust their interpretation of the arrow's flight accordingly. Thus, if you are canting your bow and getting nock-right, it could mean nock-high instead (or some combination of both).