First section is a slider and the second section is the content band. The content band is not showing the video in the background. Video is selfhosted.
I see that you are using Old version of X Theme 5.2.5 (screenshot https://cloudup.com/cf4T7dr2tb5) and latest version of Cornerstone 3.0.4. Please note that both are not compatible with each other and may cause conflicts.
Please note that both are not compatible with each other and may cause conflicts. In that regards I suggest you to please update X Theme. I am sharing our theme update guide that you can take a look to get started: