Meta and Yandex are de-anonymizing Android users’ web browsing identifiers
Abuse allows Meta and Yandex to attach persistent identifiers to detailed browsing histories.
arstechnica.com
Interesting reading on how Meta and Yandex circumvented the browser privacy features. The bottom line is that the native apps were running in the background (I wonder whether they use a foreground service which should show an indicator in the system bar), listening on several TCP and UDP ports. The "pixel" - JavaScript that site owners embed for Facebook related features, sent data to the native apps. Including in private mode.