"Check" button disabled for all questions on the page

Steps to reproduce :

• Attempt a quiz with this behaviour (Student feedback - immediate).
• Have a page with at least 2 questions.
• Submit a question.
• Write a comment without submitting it.
• Answer another question and click "Check".
• In the dialog that should pop up in your browser, click "Stay on the page".
• Now all questions that were not submitted have a disabled "Check" button.