In The Last Jedi in 2017, it is stated that Kylo Ren took students from the academy with him when he destroyed it and fled. In the 2019-2020 comic The Rise of Kylo Ren, however, his destruction of the academy is shown, but he doesn't take any students with him. Normally, I thought that SW canon followed the law of movies and TV shows over books - if information in a movie and in a book contradict one another, the movie is taken as canon. But in this specific case, the retcon came out after TLJ. So which is canon? Does TLJ still hold, or does the graphic novel have a greater sway because it came out later?
In this case there's no canon discontinuity. It's stated by an in-universe character (in this case, Luke) that...
"He had vanished with a handful of my students. And slaughtered the rest."
... which leave us well open to the possibility that Luke is simply mistaken.
In Rise of Kylo Ren #001, we see several of the Temple's students (who'd been offworld at the time of the attack) return to the temple shortly after the attack, then leave to try to catch up with Ben Solo, ultimately doing so in #004. They also make a comment about wanting to deal with Solo before speaking to his mother.
It's very plausible that Luke, having found evidence of their landing or simply noting that they didn't return to the Temple subsequently, would assume that those students were involved with Ben (noting that they were evidently still alive but hadn't made contact with him or Leia), rather than that they were adversarial to him.
It's possible that he took students with him and the comic just didn't show it.
Speaking more broadly, Star Wars "canon" is on much shakier ground than it was ten years ago. Aside from the obvious (i.e. the sale to Disney, the EU being retconned out), the policies on what is and isn't canon are subject to change without notice (in practice, if not explicitly). People who controlled canon five years ago - people who in 2017 could say "this is canon now" and make it so - are now out of the picture with no authority over canon, and the stories they told are subject to retcon or expulsion if the next person wants to tell something else.
If I may digress for a moment, this is one of the problems with legally disconnecting ownership and authorship to the extent that Star Wars has done. The old EU worked - it was (mostly) self-consistent within its own canon - because while it had multiple authors, all those authors worked under the auspices of Star Wars. They couldn't just add anything willy-nilly - the various EU novels and comics and video games were made under the assumption that they had to fit with what had come before in order to get George Lucas's stamp of approval. This was mostly a fiction, but it worked - partly because George Lucas was staying out of the Star Wars storytelling and showed no signs of returning to it, and partly because, up until TCW and the Disney sale, nobody had written a new story that explicitly retconned or contradicted someone else's previously-canonical story. As long as that unbroken standard held - as long as every new author worked within the confines of those that had gone before them - there was no need for a hierarchy of canon-authority. There was no need for readers to interrupt their reading to check what authority a particular work had to contradict some other particular work, because you could take it as gospel that the greater Star Wars story - weird and idiosyncratic as it might be - would not contradict itself.
That standard is broken. Canon is broken. And from that follows this and every other confusion you will ever have about Star Wars.
(Sorry if that turned into a rant.)