Hi again,
I checked your site in Windows 10 Firefox and Chrome and I can see the video playing too. It seems like your client is using a touch screen PC?
It’s known issue with hybrid devices (mixed of both desktop and mobile touch features). The feature loaded on mobile is different from desktop. Menus on mobile are operated by touch or click, and that’s what happening on the hybrid device.
Most modern mobile and tablet devices now surpassed desktop screen resolution. Hence, it’s harder to detect if a device is a desktop or mobile since hybrid device specs are almost equal to a tablet.
The only thing that separates them now is touch feature, now they introduced it on laptop/desktop too.
Hope this helps!