Gaited horse/breast strap

I have a Tennesse Walker/MO Foxtrotter, when I trail ride I like to use a breast strap but it seems never to fit properly and rubs a spot. I was using a wider one that came with my saddle and then switch to a thinner one and still had a problem. Am I not adjusting properly possibly?

Check out this thread. A gaited horse has lots of movement in the shoulder so a typical breastcollar that lays over the shoulder is probably going to rub. If you turn it into a pulling collar like smrobs describes in this thread Opinions about breast/pulling collars please

It should interefere less.