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preview cumulative update you may experience issues with system and user certificates getting lost if updating with outdated update media from Windows 10 1809 or later versions.
"The preview update for Windows 10, version 20H2 and Windows 10, version 2004 will be available in the near term," Microsoft

With the KB4601380 monthly "C" release preview update, Microsoft addresses an issue that leads to screen rendering problems when launching games on systems with certain hardware configurations.
This cumulative update also fixes a bug causing high CPU and memory usage on systems running Microsoft Defender for Endpoint (previously known as Microsoft Defender Advanced Threat Protection).
Other highlights included in this update: