After a brief pause in the Insider Program's Release Preview Ring, Microsoft Windows 10 released 1903 Build 18362.329 (KB4512941) for the production ring – but as an optional update. Although the update packages for the builds released in the Release Preview Ring were the same, only the package for the May 2019 update was released for production because 19H2 is still under test. However, it turns out that while the cumulative update fixes a number of issues, some users may not have a great experience.
Reddit users reported that after installing the latest cumulative update, CPU usage even rose to a high value when the system was idle and was not used. Most users who reported this performance issue found that Cortana was experiencing high CPU utilization (specifically, the SearchUI.exe process detected in Task Manager). Also, the task tray search tool will look ineffective for those who have encountered this problem, as the search click flyout remains blank. Interestingly, some insiders in the taskbar have feedback on this problem logged feedback hub. However, because the build insider was not offered long enough before it went into production, the problem seems to have slipped. In addition, the topic has not collected enough positive voices to attract attention. It is expected that the company will wait for more insider preview build responses to better address such issues.
Microsoft has not yet confirmed the error officially. The KB article for this build also did not list known build issues. There are some workarounds to resolve this issue, such as: For example, optimizing specific registry entries. However, it is recommended that you do so only if you are familiar with editing registry keys. Accidentally deleting or editing the wrong registry entries can cause other problems.
Alternatively, users of Windows 10 Pro can go to Settings -> Windows Update -> View Update History and uninstall the problematic update. For those who have not yet installed the update, it is best not to do so. The next cumulative update should include fixes from this build and hopefully fix Cortana's performance issues as well. Whether the issues are actually resolved before the next round of Patch Tuesday updates is unclear.
Recent updates were generally problematic for Microsoft, as the latest firmware updates for Surface Pro 6 and Book 2 also caused problems with CPU throttling. These issues are certainly embarrassing, as the company once again put emphasis on quality after the Windows Update debacle of October 10, 2018.
Source: Reddit (1) (2) Via WindowsLatest | Task Manager screenshots: Definitely you (reddit user)