EDIT: On the off chance that anyone's found this post while searching at all, it turned out to be both a timing and a spacing issue. See the comments below, particularly the one from LilyOfFlowers, for more details.
Is it normal in a fighting game to be in training mode, be presented with an "easy" combo, follow everything as well as you can, have the timings look right, and have it fail for unknown reasons? I'm really struggling to figure out what I'm doing wrong here, if anything. And this seems to happen in just about any game I play. I get stuck in training mode trying to wrap my head around 'easy' combos, and I get hung up on just being unable to make them link.
Putting this under a cut because I'm dumb.