There seems to be more than one index. There is the index of scanned file content, an index for apps, and maybe another one for help. There is also a query time

There seems to be more than one index. There is the index of scanned file content, an index for apps, and maybe another one for help. There is also a query timeout. If you start searching after a boot on a slow laptop you get a subset of results dependent on which index is loaded before the query times out. Kill the start menu and try again. And again. And then it works smoothly. It's quite poor.