Storyline 360: Issues restarting course from lightbox

I have a lightbox slide that discusses how to navigate a course. Within the slide is a button to "restart course". I have also included a duplicate of this slide at the end of Scene 1.

If the user clicks the button while in the lightbox, the course resumes within the lightbox. Thus, I set a grouped trigger to close the lightbox and restart the course. However, this appears to have a bug; the lightbox closes and the screen just shows three dots as if it's refreshing. After 10 minutes, it still showed the dots, and the course had not restarted.

If I click the "Restart course" button from the duplicate slide in Scene 1 (which is not lightboxed), it works perfectly.

Please advise how I may structure the triggers to close the lightbox AND simultaneously restart the course. I've experimented with switching the order of these two actions, but the result is the same. I ungrouped the triggers with no noticeable difference. I changed the trigger within the lightbox to jump to Scene 1 instead of restarting the course at the initial welcome screen. Nothing improved. Can anyone help? I saw nothing about such an issue in any past discussions. I've added a test mock-up of the presentation.