duckduckgo don't prevent website to track you or deposit cookies etc. Once you're on a website, let's say twitter, duckduckgo does nothing.

> When you view Twitter content such as embedded Tweets, buttons, or timelines integrated into other websites using Twitter for Websites, Twitter may receive information, including the web page you visited, your IP address, browser type, operating system, and cookie information. (https://developer.x.com/en/docs/twitter-for-websites/privacy)

So, if you visit a news paper that have embedded twitter post in it, twitter might know you passed by this website.