Shoulder coming out from under belt in booster

We've recently switched our 6.5yo daughter into a high back booster. She's doing soooooo much better than when we tried it a year ago! She came out of a Nautilus, and went into a Diono Monterey that we already owned. Belt fit is good, and the shoulder fit is fine as long as we route the belt so that it bypasses the belt guide ( so belt doesn't get hung up in belt guide).

But yesterday she fell asleep in the car (rare), and when I turned around and checked on her, she was far enough over to the side that her shoulder was no longer under the belt. The belt was an inch or two down her arm.

This morning I double checked the Monterey, and, sure enough, it was not at it's narrowest setting - I cranked the doo-dah on the back and got it to narrow an inch or so on each side. I've always had trouble with these seats widening out on their own, and customer service has sent me one, if not two, entirely new seats, but the problem is still there.

Any suggestions? Is there now some known way to prevent these seats from widening independently? Or should we just purchase another booster? I'm loving having the seat latched in, but budget is tight right now, so this time around cost is a factor. Oh. One more thing - the Nautilus could of course be used as a high back. But the lap belt fit is just so high. I don't like it. Yes, the belt touches her thighs, but so much of the belt sits on her belly that it doesn't look good.

Any suggestions are welcome!

Have you called and asked for a new belt guide? They know there is a problem with older guides. I would not use it without the guide. Not if that is the way she ends up.

For us getting the new headrest with the new guides solved the problem.

I would not skip the belt guide, its there for a reason. If it won't retract properly that means the seat doesn't work well in that seating position in your car or in your car at all.

Are you using the nautilus for anything? My kids and I really like it as a HBB.

Thanks for the suggestions. I was originally bypassing the belt guide at the instruction of Diono customer service. It hadn't occurred to me that the shoulder issue could be resolved with better belt routing - I thought it was a seat width problem. I've called customer service (again), and they are now sending the belt path fix. So hopefully that will resolve the problem.

Thank you for the suggestions!

You could put duct tape on the silly width adjuster. :duck: