You need uncheck the "Show content marked as adult in search & browse" under profile settings for your account.
If you can't uncheck it, then you need to uncheck the option
"Has sensitive content — This project is not suited for minors or the workplace" under game's metadata tab.
When you add a TAG indicating adult content to your game, Itch automatically checks that option (which is what really matters), if you remove the TAG, but do not uncheck the option, the game and therefore your entire account, will be marked for viewing adult content.