Microsoft has released an emergency fix for gaming issues introduced by the Windows 10 2004 and Windows 10 20H2 KB5001330 update. The issues experienced while playing games include decreased frame rate, video stuttering, and flickering textures. Microsoft has started the rollout is expected to be complete within 24 hours and that restarting the computer may speed up this process. The fix is being rolled out using Microsoft’s Known Issue Rollback (KIR) feature, which is pushed to systems through Windows Update.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-pushes-emergency-fix-for-windows-10-kb5001330-gaming-issues/