The global workspace search won't return results for files stored in Unity Catalog Volumes. Its indexing is focused on workspace assets and catalog-managed objects, rather than the underlying files within a Volume.

To locate files in a Volume, navigate to the Volume through Catalog Explorer. From there, you can browse the folder structure directly and use the search feature within the Volume view to find specific files or folders.

If you need to inspect files at scale or search based on file contents, you'll need to do that programmatically using Spark or Python.

So this behavior is expected—the workspace search and Volume storage are handled through different discovery mechanisms.