SL 360- Video within video using embedded "web object" videos

Hello,

I'm working on a project in SL 360 that offers the student a chance to watch a video, and then click on boxes within the video to show a couple of other videos. This works easily if the video files are hosted locally. Each clickable box calls up a layer with a video in it, and the video plays. Using triggers I can control what the video in the base layer does and what the video in the layer does. 

Problem is, I need to use embed codes to access the videos. It is easy enough to place clickable boxes on the "web object" and the boxes work to call up another video. The base video even stops playing when I play the video from the layer.

However, the clickable boxes that I've placed on the timeline don't stay where I placed them. I put them on the timeline at :10 and :25 seconds, but when the project is published, the first box shows up at around :05, and the second one may or may not show up.

I've tried placing an invisible layer in the timeline, over the video but under the clickable boxes, to sort of anchor them, but that doesn't seem to help. I've tried putting the rectangular boxes in the embedded video at the correct spots, and then placing an invisible click box over them, but the invisible click box wanders just as the visible ones I talk about above did.

Is there anyway for the student to be able to watch an embedded video, click on a box and go to another, embedded video? Or is the use of the online video a deal breaker?

Any suggestions appreciated!