The speed-fixing patch went out to Windows 11 a couple of weeks ago, but it still goes on in a preview. If you need to get the KB5007262 patch that addresses that problem, you should download it manually by Windows Update or you should find it inside the Microsoft Update Catalog. In the usual automatic update, it’s not working, but at least not yet I’ll be able to integrate it into a newer version at some point. Our sister site Tech Advisor has step-by-step instructions on how to download the patch from Windows directly or via a browser. Hopefully this will solve the trouble with Windows 11 for at least some users.