The suit's claims cite work done by two independent app developers at software company Mysk, co-founded by Germany-based iOS dev and "occasional security researcher"Mysk, in November last year. According to the suit, the pair's test "revealed that even when consumers actively change their 'privacy settings' and take Apple's instructions to protect their privacy, Apple still records, tracks, collects, and monetizes consumers' analytics data, including browsing history and activity information."
Another lawsuit relating to Mysk's research over Apple's data collection practices was filed in California federal court in November last year, with that case alleging the company was violating the California Invasion of Privacy Act
https://www.theregister.com/2022/11/14/apple_data_collection_lawsuit/
more here:
https://9to5mac.com/2023/01/09/apple-privacy-tracking-lawsuit/