Thank you, Everyone, for your offers of help. Unfortunately, for legal reasons, I couldn’t share the vignette. However, I can tell you that removing a timeline jump in it seemed to have fixed the issue.
Basically when a user clicked one of the download buttons, it would jump to a new part of the timeline and trigger a message telling the user to check his/her downloads folder. Removing this functionality seemed to fix things.
Thanks for your help.