That's a known issue with some seats, but not one i have heard with the nauti, to be honest.
It's been discussed quite a bit with the GN. It's definitely not a new concern, but it doesn't happen every time. The conclusion we came to is that sometimes the button connecting the LATCH strap isn't pushed through all the way. It sticks out on the child's side and rubs against her back.
Here's what it should look like-
see how there are two ridges through the back of the shell (not counting the smaller one at the end)? That's how it should be. If she can only see one on the back, then it wasn't pushed through correctly. I'd tell her to call Graco and say she compared it to another GN (as in, through this photo
) and that it's causing her child pain due to the way it's inserted. Graco customer service is generally top notch, but it they won't help her maybe she can exchange it where she bought it.
Beyond those options, I might even go rogue and remove the button entirely.
The LATCH strap has to be connected to the seat under FMVSS 225, but not for any safety/functional reasons. I think pulling it out would potentially cause less stress to the shell than trying to push it through farther. :twocents: