Pretty sure I know exactly who you're talking about because the same thing happened to me on my OG account with that person. Funny enough (but not funny at all) when I went to his profile he was no longer blocked and I know good and damn well I blocked him. So I did it again. Not a week later, there he was in my feed again and UNBLOCKED.
It's also happened with someone else who isn't popular but trolls sex writers everywhere, and I've blocked him here 4 different times, yet he magically gets unblocked.
I am sick of it.
I'm so sorry you're dealing with that too. And I care what you think, btw.