What users are reporting
https://www.bleepingcomputer.com/news/microsoft/windows-10-kb4579311-update-wont-install-may-cause-explorer-crash/
​Windows 10 users face numerous issues installing the latest KB4579311 cumulative update, and for those who can install, they are reporting various bugs, including performance issues.
Microsoft released the Windows 10 KB4579311Â cumulative update on October 13th, 2020, and since then, users have been reporting problems getting the update to install, crashes, performance issues, and boot problems.