Timeline trouble since upgrading to SL360!

Due to issues with confidentiality, I can't upload my story file here, so I apologize, but here goes:

I built a rather complex project using SL2 and have recently converted it to SL360 in order to utilize the HTML5 publishing options. I am experiencing a really strange glitch on one of my slides, however.

Basically, I have a video that plays, and a custom scrubber/seekbar below it. The user can scrub through the slide using Storyline's Player, and the custom seekbar cooperates with it.

The way I have it set up is as follows: a triangle shape moves along a motion path at the same speed as the Storyline timeline. Since Storyline's motion path animations are limited to 59 seconds (would love to see this increased), I have a trigger that says "when [triangle] finishes [motion path 1], move along [motion path 2]. This allows the triangle to move along the length of my timeline at the same speed as the SL Player's seekbar and it works great in SL2.

Now I have converted the file to Storyline 360. For some reason after the shape begins to move on [motion path 2], the audio in my video falls back and becomes out of sync with the video. Then at the end of the timeline, instead of moving to the next slide as my triggers suggest, the timeline is somehow extended! And the triangle begins moving on some OTHER motion path that does not exist, while everything else on the slide completes is exit animation. The timeline seems to be extended a good 50-something seconds, with nothing happening on the slide.

I apologize for the wordiness, this is a bizarre bug that requires some background I suppose. Has anyone had any issues with SL360's animation paths and/or timeline problems that are similar? Any advice?

Thank you!