Video file will not complete upload on MS Forms

Hi all, 

We use MS Forms to accept video submissions for assignments. A number of students have gone to upload a recording, but the progress bar has remained in the same spot, with the file not uploading. Please see an example below. 

The file limit isn't being exceeded, the video is in a traditional format (e.g. MP4) and the size limit isn't being exceeded. 

Students often also have a strong, reliable internet connection when this happens. Typically, when this occurs, we recommend that students try a different internet connection (if possible) or try again at another time, but this issue occurs frequently with different users. Different web browsers have been used to see if this makes a difference, but it doesn't appear to. 

Does anyone have an idea of other ways to resolve the above? Obviously, this is quite stressful for students (especially those who choose to submit close to the deadline).