I find mine pulls on my shoulders if I make the straps that you tighten under your arms too much. It takes a while to find a good balance and then DH changes it when he wears it !

I agree with Suse, the more weight you can carry on your hips the easier it is on your shoulders and back. Maybe play with the height around your waist too?

Glad you like yours, they're so wonderful! (Great taste in colours too )