https://wccftech.com/microsoft-fixes-high-cpu-usage-bug-two-zero-day-flaws/

Microsoft delivered cumulative updates to several versions of Windows 10 last night, including the May 2019 Update. The M19U has been experiencing a number of bugs these past couple of months, including a Cortana/Search issue that resulted in massive CPU usage for some users.

With the release of September Patch Tuesday (KB4515384), Microsoft has now addressed that particular bug. The release notes read: