Frameless pack fit help needed

I picked up an Allmansright Listen 35 during the Nunatak drop and it's an absolute beauty of a pack. However, I'm bummed because the fit just isn't quite right. Looking for advice about what seems to be the issue so as to hopefully have better success in a replacement.

The main issue is that the top of the pack sways away from my shoulders. Here's an example: https://imgur.com/a/197T98s

Even when I tighten up the straps or loosen, rearrange gear, whatever, this is the case. My torso length is between 17-18 inches. The Liten 35 is size 17in. The framed pack I use for heavier loads is the HMG 2400 and the medium fits great. My shoulders are rounded and my posture isn't great.

Looking for insights into what's up with the fit of this pack. Is it a size thing? A strap thing? Just not a good fit for me? Does anyone have suggestions for other frameless packs that I might have better luck with? I love the feel and freedom of the frameless pack, just want to get one that is a better fit for me.

Edit: I don't normally carry the tent on the outside, but this was the only profile photo of the pack - I realize that's the first thing people will probably point out. I've tried nearly everything to make this pack work because I love it (shifting gear around, tightening straps more, loosening straps, using a detachable hip belt to keep it in place a little higher). It always pulls away from my shoulders.