What makes the "start menu" search find the app only on the second try?

Finding the same application on the second attempt shows inconsistent search behaviour, but it does not identify one universal cause. Search-process state, application registration, and indexing can all require investigation; repeating the query does not prove the index is corrupt.
Record the Windows build, affected app names, and whether the first attempt fails only after sign-in or also throughout the day. Confirm that those apps appear in the Start application list and launch normally.
Install applicable Windows updates, then follow Microsoft’s Search troubleshooting procedure to restart the search process and test again. For Windows 10, Microsoft’s guidance identifies SearchUI.exe; use the instructions appropriate to your actual version rather than terminating unrelated shell processes.
Reserve a Search reset for a persistent reproducible problem, following Microsoft’s documented procedure. Avoid deleting registry keys or package folders as an initial experiment. If it continues, submit Feedback Hub feedback showing identical searches returning different result