I checked your site and yes, the video does not load. And, it's not intermittent. It really does not load on my end.
According to our Performance article, you should exclude the theme's resources from minification because they're already minified. Concatenation or combining code into one file is also not recommended because JS functions require a specific loading order and concatenation can mess it up. It's recommended that you hire a qualified web developer to analyze the scripts in your entire WordPress site and he/she will be the one to optimize it. We do not have support for optimization issues.