An issue existed in the handling of tabs displaying picture in picture video. The issue was corrected with improved state handling. This issue is fixed in iOS 13.4 and iPadOS 13.4. A userβs private browsing activity may be unexpectedly saved in Screen Time.
https://support.apple.com/kb/HT211100
https://support.apple.com/HT211102
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-9775