[Tamagotchi Music Star] Can't even do a Practice Session without them getting sad?

I do mess up, and I see why they should get sad, but I completed one of them fully and they still get disappointed, like I either missed something or I wasn't fast enough. I swear, this Music Star is starting to get me angry with the practicing. Like I did get an OOX, but the X is still taunting me. Like the music skills and everything else are fine, but the practicing is apparently not enough.

Should I be more quicker (as the buttons seem to be laggy even though I press down good enough)?

UPDATE: I guess it was my slowness, cuz I just completed a session (or it just decided to be good to me). But I still don't get it...I swear the buttons are just really laggy.

awww I can see this leading you into a decline. "It was the Tamagotchi I say...the Tamagotchi!" it sounds like a pain!