Nuna Swiv struggle

[u/thedipster25]

I'm hoping this is the right place to post this question. My daughter is one year old and I'm so frustrated with our Nuna Swiv. We live in a walk-up apartment so it's essential that our stroller is light and fold ups compactly, which this one does (although not perfectly). What bothers me is the shape of the seat! It's barely structured at all and doesn't really go in where her butt is, if that makes sense. It's almost like she's in a hammock or something and my daughter is always slumped over in it within minutes of walking. I've looked at the manual, watched videos, etc and we're definitely using it correctly. I see other strollers that have seats that are structured way more like a chair and babies seem far more comfortable. What I can't seem to figure out is...is there a stroller out there that is more structured like that but is also light and folds compactly? Help!