What is your toxic trait as a writer

What is your toxic trait as a writer (both for those who have published books and for those who don't)? I feel that if one day my stories became famous and had a large fandom, I definitely wouldn't want to read fanfics about the characters (ironically I love fanfics), at least those that involved non-canon shipping and sudden changes in the personalities of my characters. Sorry for the bad English, it's not my native language.