Remove all adult content tags and descriptions, and then, in the metadata section of the dashboard, uncheck the option that says "Has sensitive content."
After that, you'll have to wait for the staff to review it. If they don't, contact them again and clarify that the content is just a demo without NSFW content.
Your game is still nsfw.
The message board rules discourage asking this type of question. (You will not get an answer to tickets about indexing and such, but they will eventually work on the issue. Waiting times are maybe 40 days and longer currently in my estimate. Which currently is pointless on your game, since it still is nsfw and has payments.)
If your game will have nsfw, do not promote your demo version as sfw. What you think is nsfw and what Itch thinks is nsfw might not be the same thing. It is not the same as an age rating. Your game could be rated 12 in strict Germany and still be nsfw on Itch for having naked women in it.
Tell people that buy now, if they will get the full version later. Or if you will release on Itch at all. Note: anyone that gives you money will unlock your project page, even if you set a minimum price later.
