Video flow won't save

Hello!

I am developing a training on the background of our company. For part of it, I interivewed our executive team memebers and put them on a slide. There are multiple videos per slide. I created transitions for the videos which is working fine. However, oddly enough, the placing of the video changes every time. For example, I'll make video 1 end at 35 seconds and then transition into video 2. It works once and then when I go back to double check that the flow is right, video 1 is now cut off and I need to extend the video to 37 seconds. That flow will work a couple times and then the next time I go into storyline the flow is off again and I need to adjust the ending to 30 seconds (or whatever it may be at the time). It constantly does this and will not save the correct sequence.

I've tried locking all the videos after I adjust them to end and start at the appropriate times but I still run into the same issues.

Any suggestions?