BUG: Can't 'Preview' Storyline Timeline.

It's about as straight-forward as it sounds; without any rhyme or reason, I will suddenly be unable to 'preview' the timeline of a slide or layer in the Storyline editor. I can click 'Play' or press Space and... nothing happens.

So far, my workaround has been to 'Select All' (CTRL + A), 'Copy' (CTRL + C), and then open a new Storyline project, and then go to the 'Paste' option and right-click to retain all durations, start times, options, etc.

'Oh, so the issue must be with the project file!' Wrong. Halfway through editing a copied single slide in a 'new' project file, I was once again unable to preview the timeline. So, I copied it into a new project and it was fine. I could finish the slide without issue. I did the same for two more slides, no issues, but then it occurred again on a slide after that.

Additionally, this issue has occurred on multiple project files for entirely different projects, implying that it shouldn't be an issue with a single asset or project file, as its being reoccurring across various instances with different variables. 

I thought the issue might've been with a recent update, and so I hesitated to update Storyline again today, as I have multiple projects I am attempting to get out the door and don't want even more Storyline-related obstacles to go through. So, I updated Storyline and... the issue is still there.

Once I am wrapped up with this set of projects, I plan on doing a 'full'/'deep' uninstall of Storyline 360 (including running the batch file to hunt down any remaining files) and reinstalling it again, and will update if it makes a difference, but in the meantime, I'm posting to see if anyone has any solutions, workarounds, or similar experiences that have been occurring as of recent. I know to file a ticket with support, but I also know 3, 5, maybe even 7 years from now someone may have the same issue and hopefully this post will eventually contain some solution and save them some time.