Microsoft has rolled out a Cumulative patch to the Dev channel today.  This is KB4581021 Build 20211.1005 that came to the 21H1 version. This is a testing update for insiders and does not include any improvements or fixes.

You are able to download KB4581021 automatically unless you haven’t distorted the default Windows update settings.

KB4581021 for Windows 10 Build 20211.1005 in Dev Channel

A day before yesterday, Windows 10 Build 20211 was released with some new features and improvements and today this cumulative update has arrived. The update is only designed to test the servicing pipeline. This will increase the version to Windows 10 Build 20211.1005

You can download manually the KB4581021 from – https://uupdump.ml/known.php?q=20211.1005

Source – Windows experience blog.