From Bleeping Computer.com "
The privacy-focused DuckDuckGo browser purposely allows Microsoft trackers on third-party sites due to an agreement in their syndicated search content contract between the two companies.
DuckDuckGo allowed trackers related to the bing.com and linkedin.com domains while blocking all other trackers.
In spite of what you may think, or see in their ads, you are NOT PRIVATE when you use DuckDuckGo.
Google can determine what sites you visited and the searches you made.
The government can determine your search and browsing history.
DuckDuckGo proved it themselves that there is no such thing as a private search engine.