Question Strap issues with Britax Frontier?? Help please!

We have a Britax Frontier and are completely baffled by an issue we have getting the straps to move. Not installed in a car, or installed in a car with no kid sitting in it, the straps slide freely to tighten no problem. But.... as soon as there's any resistance applied to the straps, like a kid is sitting in the seat and the straps are touching their body, the straps become nearly impossible to move to tighten them! Our 8 year old daughter (who still uses the 5pt harness because she can) can't get them tight enough even bracing her feet against the seat in front of her and it takes a few minutes of an adult huffing and puffing and yanking to make them tight enough, so something isn't right, but we can't figure out what it could be!

We've taken it out of the car, watched from the front and back as the straps are tightened, with and without kid and we can't see anywhere there would be anything inhibiting the strap movement. We've even experimented with just providing a bit of resistance with our fingers, no kid in the seat, and the same thing happens.

We otherwise love the safety and how high it's able to go in harness mode but are just totally perplexed as to what's going on! We know other people with Frontiers and they don't have this problem. Thanks!!

Hi. I believe the issue lies when the Frontier is installed and the vehicle seat compresses into the harness adjuster strap. One solution would be to not install it so tightly—but still snug enough so that it's within the moves-less-than-1"-at-the-belt-path test. Another would be to snug up the harness and leave it there and not adjust it again.