6. Seeing red
Red marks left on the shoulders where the straps usually fit can mean that you are relying too much on the straps for support and not enough on the band, which is better designed to accommodate the strain. This is another case that could be due to improper adjustment of the straps, forcing them to provide more support than they were intended to. Try loosening the straps a bit and if that doesn’t help, you might find relief by choosing a larger size.