The code shown passes the test, but the example the right hand column fails: tabbing never stops on the Search or Submit field.
It’s a bit tricky and hard to see on the page, but to demonstrate, click on the output below the code, then hit Tab. It should focus on the whole preview on the right (on Firefox). If you hit Tab again, it will focus first on the search input, then the submit button.
EDIT. On Chrome it should focus immediately on the search input.
I use Chrome, but in my hands, the code shown only focuses on the three links in succession, never on Search or Submit.
But in another example I posted where the test passed and the HTML failed, the problem was a syntax error elsewhere in the HTML.
The syntax error in the previous case was a residue of my trying something that didn’t work which remained uncorrected. I suspect something similar is happening here. I’ll look for that in this example, when I get back to it.