Mine isn't like that but there can be a few reasons I'd guess at:
- YouTube recommends you things other people in your household watch (which can extend to random people if your isp uses cnat and doesn't give you an individual ip).
- This one is more of a guess, but I'd assume a lot of people would click on that content, so if you never watch shorts maybe their algorithm just gives you the default recommendations.
- If you watch adult content without protecting your privacy it's most likely associated with your account in their recommendations.