Block them and move on, no engagement will be far worse for them than negative responses.
I’d rather not leave people spreading disinformation unchallenged / unchecked. Someone else might read their comments and think that’s the right opinion to have.
Oh absolutely report them first, but remember, a simple downvote and then (report+block) means they’re shouting into the abyss.
It’s technically not disinformation. Just a flawed conclusion. Politely pointing out alternative, more accurate, ways to look at it is the recommended method.