Modal trunks recommendation?

I've decided to try modal, and the first ones I got where David Archy, these specifically. I'm very happy with the material, and mostly the fit, except that for some reason they pull my cheeks up from right below them. It's mild, enough that pulling them down makes it go away until slowly settle back, but the combination of my sensitivity and the low pressure everywhere else makes it annoying.

I'm not sure why they do that. I probably do have a bigger behind relative to my waistsize, and I noticed that the section between the legs is wider than on my current ones. Theres also a seam right around there, but that's on the current ones too, so it would have to be a detail of that.