Most of the times I've had it are on iOS, and no amount of tapping or putting it in full screen mode where you can use the native video controls will make it lo

Most of the times I've had it are on iOS, and no amount of tapping or putting it in full screen mode where you can use the native video controls will make it load. I wonder if they're trying to serve WebM or some other unsupported codec to iOS devices by accident, but I'd think that would have some kind of error indication instead of a black box.