Neko-Sama

hey guys, i've been learning i-no combos and i've been having trouble landing the j.s xx 632146s after hcl 6frc6. whenever i hit the j.s xx 632146s, for some reason it hits in a way that doesn't allow me to combo 5h afterwards. i sort of gain a bit of upwards momentum when landing the 632146s instead of falling straight down. could any of you give me some advice?