There’s no timing required to cancel special moves in this game. You can input them as early as you want as part of the string, so if it’s not coming out, you’re doing it too late.
By the way, I know you said 1 2, but did you mean D1 2? You can’t buffer directional inputs like most games, so if you’re holding Down for 1 2 and rolling to Forward for the Lightning Kick, that won’t work.
i know but i cant do it fast enough, so i try to do d1d2 and then let go and do df1, i refuse to use my fightstick for this game cuss it doesnt seem to need it all that badly plus i hate plugging it in and sitting up and bringing to friends and all that jazz.