When an animation occurs at the top of the page after I make a Canvas Submission, namely a confetti shower, the Next button disappears. Nobody seems to know why; this is in updated Windows 10 OS using both Chrome and Firefox browsers (updated), and Zoom settings at 100%. If I log out of Canvas then log back in, the Next button is now present on the submission page and I can forward to the next, "Wrap-Up" page, and thereby officially complete the lesson. As I noted this, I have just logged out and logged back in, awaiting the instructor's grading, but if someone else does not know this, he/she will be waiting a very long time as the instructor will not see a lesson completion being indicated.