I just installed my new RA. When I grabbed the seat to check to see if it was a solid install, the seat slid sideways a bit, but without the base. Where the seat meets the base, my seat will slide side to side a bit on the rod that attaches them. (at the upside down "V" there is a black "cap" on each side that I assume has a rod between- that is what moves- caps and all) Is this normal? I checked my MA and it doesn't budge a bit on the connection.