I don't think your humour is broken at all! I've laughed at several moments in She-Ra too.
A while ago I straight-up walked out of the room after one of my friends (-ish. He hangs out with us but I don't really like him) showed my other friend a screenshot of a video, which they seemed to find amusing. I'm not going to say what was on that screenshot because it's certainly not acceptable to write here, and frankly, I don't ever want to write that word, but I will explain that it involved a racist word. Both of them are white, and I'm white-ish, by the way.
At first I didn't get the joke due to it being spelled wrong (yeah, I'm pedantic). Eventually I said something along the lines of, "it looks like a really horrible word spelt wrong, but I know you wouldn't be laughing at that, so..." and they started to look a bit awkward. The guy then said something, I can't remember what, but it basically confirmed my suspicion. And then I just walked out and didn't return until the day after.
The worst thing about it was that when I talked to my close friends about it, most of them tried to support him. The other friend (who I'm still close with) explained that the pair of them hadn't actually found the 'joke' funny - they'd been laughing at how weird it was that the person who made the video found that funny. But I kept feeling pretty uncomfortable.
The aforementioned guy has said several things since that I really don't like, although he's part of the group so I just have to deal with it...
Welp that was longer than I intended sorry about that- What I'm trying to say is, you're not alone and you shouldn't have to feel bad because what he says is wrong. Your humour isn't broken and we all know that. <3/platonic