Video plays problems in review 360

Heyo just working to see how to add our notes to this thread. It's perplexing...

Our teams have been having video playback issues on many if not all our video-only content in SL360 Review links for about a month or so. Specifically for Chrome browsers. Edge sometimes isn't an issue yet Firefox has been our go-to for our QA to test courseware as it is the least to get stuck on video playback. 

Basically, (sometimes) a video-only slide will play in a course for the first few seconds and then the seekbar will stop and the loading bar will animate for a long time. Sometimes playing the video much later like 10-15 minutes depending if at all. Or, sometimes still you can hear the audio play but not seekbar/video movement. I have been working from home all last year and never saw this til about November 2021 and I have pretty good network bandwidth at home so most videos plays fine.

We haven't made a post about this in Storyline forums as I've seen this issue in Chrome with other sites that plays embedded videos like Motion Array and Envato Elements. YouTube seems to be ok and so do most social media sites as well as in the SL360 authoring tool when previewing.

So my thought is maybe it has something to deal with the video Codec? Dan's thought above of importing a lossless .AVI got me thinking maybe the issue lies there.

Internally, our teams uses After Effects to make videos for our courseware and compresses them down to an MP4 video either via Media Encoder or another 3rd party tool called Handbrake. Then, we import these into SL360 so the project files don't get too big.

Never had issues like these before but begs the question...

Is there a video codec flavor Articulate Storyline prefers to use when playing in Review links/on the web? Any insight on where to go to improve video playback would be much appreciated again as it may be more of a global video web-standard thing than just the SL360 authoring tool.