Quiz timer doesn't work properly when multiple quizzes draw questions from the same question bank

That's correct. But if you look further, 30 minutes are assigned to Quiz 1, and Quiz 1 is pulling data from Bank 1. The same applies to the other result, which calculates time for Quiz 2, and it is also pulling data from the same Bank 1.

The first screenshot was taken after publishing your original .story file to the web. It shows that both timers are running simultaneously while the Quiz 1 is in progress. The first timer is visible on the slide, and both timers are actively tracking their elapsed time in the background. The second screenshot was captured during Quiz 1, which pulls questions from Bank 1, while Quiz 2 is configured to pull questions from Bank 2. Here, we can see that only the first timer (180000 ms – 30 minutes) is running, while the second timer for Quiz 2 is paused exactly as expected.

Try this:

In your original .story file, set the time limit for Quiz 1 to 1 minute, and for Quiz 2 to 2 minutes. Use only Bank 1 for both quizzes. Preview the project and select Quiz 1. You’ll notice that the timer starts counting down from 2 minutes instead of 1.

In testing, the quiz ends after 1 minute, just as originally set and expected even though the timer initially starts from 2 minutes. In other words, it seems that the first timer is running correctly in the background, but the display initially shows the timer value set for Quiz 2.

Of course, this is only my opinion, based on my own findings and conclusions, and is not supported by any official Articulate documentation. At this point, I suggest contacting Articulate Support for further investigation, or consider assigning a separate question bank (e.g., Bank 2) to Quiz 2, which has proven to resolve the issue.