Hi!
Have looked around but cannot find anyone with this problem (just a very old post):
I have added media to the lesson as described, to be visible in a pop-up on start. But there's no automatic pop-up when I start the lesson, just the link for a manual pop-up (and that works fine).
All pop-up blockers turned off and tried in different browsers.
Moodle versions 2.6.4 and 2.8.5