Hi,
That search bug can be really frustrating when you’re used to it just working. A couple of quick things usually clear it up: sometimes the Windows Search service itself just needs a restart, and other times the search index gets corrupted so rebuilding it helps a lot. There’s also a built-in troubleshooter for "Search and Indexing" in Windows settings that can catch common issues automatically. Most people find one of those three fixes does the trick, so worth giving them a try before diving into deeper repairs.
By the way, does your search fail completely, like even typing "Notepad" shows nothing, or is it only with files on your PC?
Kind regards,