Dear James,
thanks for uploading the quizzes to my server.
As you have summized, the second quiz is not working as expected because the JavaScript is in an external JS file. QuizPort is expecting the JS to be in the quiz's HTML file, so that it can add the extra code to be able to return results to Moodle.
You can get this quiz working with QuizPort if you regenerate the HTML file without the external JS file. Alternatively you can run the quiz from the ".jqz" file.
Interestingly, the HotPot module would be able to handle this quiz, because it modifies the JS once the quiz has loaded in the browser, so it doesn't matter if the JS came from the HTML file or an external JS file.
Well done for finding the cause of the problem
best regards
Gordon