If using Ctrl+F for Find does not work in your browser, try the unformatted Printable/Searchable version.
As of Feb '19, it is working for me in Chrome and Opera, and not working in Firefox and Edge. (??)
If there are additional notes for a file, there will be a green-boxed Notes near the top right. Clicking on this will show the note(s). To close the notes, use its X.