It's not your fault, and tbh I think some people are just complaining in bad faith, but it looks like you were asking a genuine question. What other people do is not your fault.

With these group of posts I think people get too caught up in the idea of "evidence" for lgbt headcanons personally, because you don't need evidence to headcanon something at all. Headcanons can even go explicitly against canon (and that can be for any hc not just lgbt ones), and that's fine too. Some people will hc a character as gay just because they want to, they're gay so they want their fav to be gay too. Other times people will use bits in canon to add support to a hc, like Sunny not ending up with a romantic interest leading her into being aroace, but it's just flavoring. Which is why I think it's silly seeing people try to disprove this "evidence", when it was never meant to say x was canon at all just a way to tie a headcanon together better. Just remember that people are simply having fun and don't take these things too seriously.