Microsoft will have to patch the patch. A recent patch designed to eliminate unwanted CPU spikes associated with Windows Search has apparently broken Windows Search.
At least it has on my machine. Other threads on Reddit report that the entire Start menu has vanished. More tellingly, Microsoft has acknowledged the bug, and has said that it is working on a patch for the patch.
Originally, a “small number of users” saw a spike in CPU consumption after installing the latest update to the Windows 10 May 2019 Update, or KB4512941, Microsoft reported last week. Those spikes were apparently tied to users who had decided to block Windows Search’s ability to search the web. This week, Microsoft issued patch KB4515384 to solve the problem. Unfortunately, in fixing the CPU spiking problem, the patch presented new problems for Windows Search and, in some cases, the Start menu.