You're not alone. Trying to get the last emote is legitimately one of the most frustrating gaming experiences I've ever had. It's fine to have a challenging minigame, but putting an emote at the very end of it was honestly a huge mistake. None of the other emotes are even remotely difficult to collect. I really hope they fix this, because making the grid move slower was not enough of a solution. If they don't change it significantly, I'd imagine a huge portion of players will never get the final emote, myself included. After about 30 hours of trying to get it, I give up.
In what way would that work if it phases through you anyway? I've tried that at least twice and it only goes through me, standing or jumping. *update, okay so now I don't phase right through it anymore but I have to stand on the right spot. Still to get away from the grid is irritating considering I can't find as many shortcuts as floor is lava, which is the only minigame I could complete but there's nothing up top sadly.