I have built a quiz in New Quizzes. I created a Stimulus question with a video. The video is in the course's uploaded media and it is also under User Media. I can see and play the video in Build mode, but in Student View, the video disappears. 

I have tried logging out and logging back in. I have cleared my cache. I have deleted and re-added the questions from the bank. I have also completely created a new question. 

In the first picture, you can see the video thumbnail, but in student view it's gone. Thanks in advance for your help!