Microsoft is rolling out a new build to the 21H1 version in Dev channel in the form of Cumulative update. KB4586238 is the release that increases the OS to Build 20231.1005. They have announced about the build right now but you will receive the same in the evening when Tuesday patches will be rolled out.

You will receive the insider build automatically if you’ve not tampered with the default Windows update Settings. See the full detail of the previous build Windows 10 Build 20231.1000 (rs_prerelease) Dev 21H1 Features, Change, Fixes

KB4586238 Windows 10 Build 20231.1005 Dev Channel is Available

Here is KB4586238 Windows Build 20231.1005 changelog –

This LCU doesn’t contain any new thing but is designed to test our servicing pipeline.

The cumulative update identified and settled the bug that caused the previous Cumulative Update to not install. This was reported by Windows Insiders last month.

How to download the insider Build and install

Straight away, press Windows logo key, type updates and then hit the – Enter.

Once the Settings page prompts, click the – Check for updates.

Wait until the full build is downloaded and click the – Install now.

Source – Windows insider blog.