Background video shows bug before video actually loads on Mobile

There is a bug on my homepage in the hero section on mobile. When loading the page, before the background video plays as it should, it shows the first image of the video in small as an overlay before that disappears and the background video plays as it should. The video is hosted on the website itself, not Youtube or other. Can anyone help me on this?

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