Microsoft has released a second update for Windows 10 build 21364 in the Dev channel. It carries build number 21364.1011, and there's nothing new, as it's just testing the servicing pipeline.
Build 21364 RSS
Microsoft added a known issue late last night to the most recent Windows Insider dev build 21364 in that a Cumulative Update for .NET Framework 3.5 and 4.8 fails to complete installing.
Microsoft has released this week's build of Windows 10 to Insiders in the Dev channel. Build 21364 includes the ability to run GUI Linux apps through WSL, improvements to Task Manager, and more.