Unexpected result from the tabbing test

[carolinan]

I got this result in the terminal when testing Twenty Twenty-One:

Tabbing is not working as expected
Expected: <a class="skip-link screen-reader-text" href="#content">Skip to content</a>
Current: <a href="http://localhost:8485/?cat=18">years</a>
See: https://github.com/WordPress/theme-review-action/blob/trunk/docs/ui-warnings.md#should-have-logical-tabbing

Screenshot from the output/screenshots/tabbing-test folder:

Do we know why the tab did not start from the top of the page? What went wrong?
There is a generated gif called screenshots-in-order.gif inside the folder but I am unable to open that.