Plugin disables bg video after cache runs long enough

I love JCH Optimize. I’ve used it for years. The only conflict it seems to have with my site is that once the cache is filled or sits long enough, rather than the video itself, it somehow sets my site to display the poster, which is called like so:

<video autoplay="" loop="" poster="https://jroberts.net/wp-content/uploads/2015/05/shark_parade.png" id="bgvid">

Once I clean the cache, the video works as expected again.

I’m happy to provide any additional details that might help. I just don’t quite understand the issue well enough to even know what I should provide. All I know is that every now and then the video stops working and my site shows the poster instead. I clean the cache and everything works as expected again.

Here is all the html for the video.

<section itemscope="" itemtype="https://schema.org/CreativeWork">
<div class="shark-parade" itemprop="video" itemscope="" itemtype="https://schema.org/VideoObject">
<meta itemprop="name" content="Shark Parade">
<meta itemprop="duration" content="T20S">
<meta itemprop="thumbnailUrl" content="https://jroberts.net/wp-content/uploads/2015/05/shark_parade.png">
<meta itemprop="description" content="Actual shark parade, caught on camera!">
<meta itemprop="uploadDate" content="2015-08-28">
<video autoplay="" loop="" poster="https://jroberts.net/wp-content/uploads/2015/05/shark_parade.png" id="bgvid">
<source src="https://jroberts.net/wp-content/uploads/2015/08/shark_parade.mp4" type="video/mp4">
<source src="https://jroberts.net/wp-content/uploads/2015/08/shark_parade.webm" type="video/webm">
</video>
</div>
</section>

The page I need help with: [log in to see the link]