Hello @superDupar115
Thanks for posting this in the global Canvas Community.
Unfortunately, I would not be able to tell you why that happened without looking at your specific example. If the quiz was listing that it was muted, that typically indicates that the instructor has hidden the scores and answers on the quiz. They will typically do this to prevent cheating and such.
From my understanding, I know that Canvas support highly recommends that you only have the quiz open on one device at a time. Having it open on two devices at the same time can cause issues when you go to submit and may result in your responses not being collected.
Hopefully this helps!
-Colton