Why isn't my background video playing on mobile devices?
Splash background videos are visually appealing, but can be complicated to deal with on mobile devices.
When you add a video background to a Splash Block, any client who views the page on a mobile device will see the video's thumbnail image instead.
Many mobile operating systems have chosen to block background videos to save in data usage for their clients. Because of this, Qwilr will always display replace the Splash video with a still image on mobile screens
If you have admin access to the video on YouTube, you'll be able to set or change the thumbnail image via the video settings on YouTube's side.