Next button isn't triggered by timeline
Having an issue in Storyline 1. I've created a course that's uses online videos of instructors. I've inserted the videos from a website, using an embedded link to vimeo.com. The way I'm keeping the user from skipping is by using a variable that changes when the timeline ends. Before the timeline ends, when the user clicks on the Next button it shows a layer that says "You must complete the video". Once the variable changes, then clicking on the Next button advances to the next slide. I'm adjusting the time of the Online Video to the correct length of the Vimeo video in the timeline, so the timeline is tied to how long the video is.
It's been working ok so far, but I've had a few students reporting that on some video slides, not all but some, once the video ends the next button doesn't advance. They will wait for awhile after the video finishes but it just keeps showing the incomplete layer. However, they can advance by clicking on the next slide in the Menu, even though the Menu is set to Restricted. So, it looks like the system is recognizing that the timeline ends, but not the Next button.
This is happening on different courses and only for a few people, so needless to say there are many intermittent issues and it is frustrating. Any ideas?