The way the load is distributed across the straps causes it to cut into the shoulder instead of spreading the weight evenly across the width of the shoulder strap. Using a section of webbing sewn down the shoulder strap that is slightly wider than the material reinforcing the strap setup currently may fix the issue. Just something to spread the load more evenly once the top buckle is strapped across the chest or back
The only toddler carrier we’ve ever owned was a Tula and we LOVED it, but we lost it and I got curious about other options! The fabric this is made from caught me off guard, but it’s soft and nice and seems REALLY breathable which is great because my son is a sweaty little guy, haha... and the straps are so different. They come completely unhooked from the body of the carrier and you can cross them — I actually have to because otherwise it’s really kinda too big for me... I’m not sure if this because it should hold a larger child? Lol Or if they’re supposed to cross because that’s really how it’s designed. It fits my husband a bit better than it fits me, but he didn’t try to cross the straps either. I plan to play with the straps and where they tighten a bit soon but overall it’s a great carrier!