Problem with header video on mobile

Hello, I am using Euphony Free WordPress Theme and I have a header video on the home page, which works fine for the desktop version, however it does not work for mobile/tablet versions. For preview mode it seems to work fine for both versions, but when I actually load the page on live tablets/mobile phones, it shows a static header image instead. What should I do to get the video to show on the home page for all devices? This is the website I need help with: https://oscalamares.com.br/ Thank you in advance!