When I write a twist in a story, I don’t think in terms of “what will people never guess”, I think more like “How do I throw out just enough hints that some people start to catch on while the majority are still left guessing, but when the twist happens everyone can go back and see all the hints to it and realize it was planned all along”
Because frankly, people who change their twists just because some people figured it out are cowards who only care about shock value rather than the glorious art of suspense and mystery.
my advice, take some pages from the best twists in modern media. Like grunkle ford and pink diamond. They even had a red herring that fooled the fans for a while but still left enough clues for the real answer to be plausible