why isn't it saying I bought the game when I updated it now says require demo for things I had  :edit I bought the game now it says buy again WHY

If you are logged into your itch.io account, you can download the full version without paying again. You are the first one who have trouble with that. Can you please descripe the problem a bit more detailed, so that I can help you? Or you can still write an email to the itch.io support, which response very fast.

And which version are you trying to use?