If the text wasn't generated, did you run it through other tools like grammar checkers or translators? We're finding that such tools also leave strong LLM imprints these days.

Your posts have been getting classified this way so frequently that the odds must be pretty low that these are all false positives. More likely you've been using some text-altering tool which one doesn't normally think of as genai. We've had dozens (maybe even hundreds by now) of email threads with users about this, and that's almost always what turns out to have happened.