Can you force videos to preload?

Hi!

I'm working on a Storyline360 project, and I start with a navigation slide that has 5 buttons that take them to 5 different slides. Each slide has a 1 minute video on it. (.mp4) Because the videos are loading with "progressive download" the playback stutters a little, and is out of sync with the audio.

Is there a setting where I can force all 5 videos to preload, during the initial course loading? 

I'd rather my users see a fun message during course preload, rather than have out-of-sync videos, and stuttering during progressive loading.

Thanks