I am suddenly having this exact same problem and it’s driving me bonkers. My video format is an .mp4 and is only 2.6mb. I’ve tried adding as a new BG video element and I get the same ‘check connection error.’
Here’s the READ-ONLY link: https://preview.webflow.com/preview/unifyamerica?utm_medium=preview_link&utm_source=designer&utm_content=unifyamerica&preview=5d7bda8181a059eeaa0a65c92eecea63&pageId=6120071d497d871059665f25&workflow=preview