I am one of those that sometimes gets two quizzes online in one day. Often if a quiz is in the queue a long time I make several more while I wait. When one goes on, I submit the other. If there is a long queue, especially in music, the editors sometimes get together and empty out that catagory. So if one quiz is accepted and I submit another, sometimes I'm submitting to an empty queue. That is how you can get two quizzes online in one day. I don't know about the same time, that's odd!
All of life is NOT a workout!