https://www.bleepingcomputer.com/news/microsoft/windows-10-kb4601380-update-fixes-screen-rendering-issues/

Microsoft has released the KB4601380 non-security update for all editions of Windows 10, version 1909, and Windows 10, version 1809, with fixes for screen rendering and Microsoft Defender for Endpoint high resource usage issues.

After installing this preview cumulative update you may experience issues with system and user certificates getting lost if updating with outdated update media from Windows 10 1809 or later versions.