Thanks for uploading the 3MF, it really helps take the guesswork out of answering questions like this.
Your expecting too much of the technology.
The cause you’re seeing is the interior filament shrinking at a rate different from the surrounding walls because there is a difference in material thickness.
Your model is only 4 walls thick and 3 layers where this feature appears. You appear to expect the single outer layer to not be influenced by the one behind it. That simply won’t work.
The only thing you can try in order to diminish it–but not get it to disappear altogether–is to change the wall sequence from the default of inner/outer to outer/inner. This will give the outer wall a chance to firm up first.
Also, slowing down the outer wall speed may help but I doubt it will eliminate this.
Alternatively, you can design the model to have thicker walls.