Noticed it was my turn to get the inexplicable block on X. Couldn't tell you when it happened since it wasn't due to an interaction and she has previously responded to my rare replies positively a time or two. Not blocked by her alt, though. Lol.
Not that there needs to be any logic to it, but I did often give her posts a courtesy like and I wonder if she watches her likes like a hawk and if your consistency slips, she punishes your betrayal. Who knows.