My new 2019 Grand America came with the low seat. When I flipped the front metal plate from low to high, the low seat will no longer go into place in the back. (It’s a one piece seat). I’m wondering if only the high seat works when the plate is in the high position. I’m confused because with my RT the same seat could be used no matter which position the metal plate was in. Anybody know if two different seats are needed for the two different plate positions?