if you are searching for something for the first time (or after caching invalidates), it seems like it prioritizes search sources that have already completed.
on my computer, that means web-search almost always completes first. So most of the time if I type in something "new" and don't wait, it'll bring up Bing.
Sometimes it looks like "downloads folder" file search completes before Installed app search completes, because on one occasion I typed in an app's name and it launched the INSTALLER for the app.
once all the searchs resolve it behaves "as expected". I am very surprised if you don't have the same symptoms I'm describing. Why is your computer behaving different from every Win11 install I ever interact with?