Narrow the question first

  1. Confirm the folder in the sidebar.
  2. Press Command-Option-F and enter a distinctive word or phrase.
  3. Open a result and read the surrounding text before changing anything.

When the result is absent

Check spelling, scope, and whether the file is available locally. Try a shorter phrase that does not cross a line break.

Review before replacing

Searching is free. Replacing across the folder changes files and deserves a separate backup and review.