Background video on my weebly website is playing well on PC but not on mobile/tablet at all. On mobile devices, I see an image which looks like a scene taken from the video.
Background videos do not play on mobile devices. This problem is not specific to weebly only as most (if not all) website builders/plugins have background videos disabled on mobile devices.
The image you see in place of the video is what we call a “fallback background image” which appears in place of the video on browsers and devices that do not support background video.
If you’re using weebly header section or main content section to have a background video, it will automatically take a scene from your video and it put up as a fallback background image. You cannot decide what image appears as fallback.
Some external plugin/tool allows to upload a fallback background image of choice.