Vimeo iframe несколько видео не прогружает

Подскажите, по какой причине могут не прогружаться видео с vimeo вставленные как background.

<div class="center-block">
    <div class="row">
        <div class="col-md-4">
            <a data-fancybox href="https://vimeo.com/215478623" class="vimeo-popup"></a>
            <div class="vimeovideo" data-src="215478623">
                <iframe src="https://player.vimeo.com/video/215478623?title=0&byline=0&portrait=0&badge=0&autoplay=1&background=1&loop=1" width="400" height="230" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
            </div>
        </div>
        <div class="col-md-4">
            <a data-fancybox href="https://vimeo.com/215700815" class="vimeo-popup"></a>
            <div class="vimeovideo" data-src="215700815">
                <iframe src="https://player.vimeo.com/video/215700815?title=0&byline=0&portrait=0&badge=0&autoplay=1&background=1&loop=1" width="400" height="230" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
            </div>
        </div>
        <div class="col-md-4">
            <a data-fancybox href="https://vimeo.com/139554482" class="vimeo-popup"></a>
            <div class="vimeovideo" data-src="139554482">
                <iframe src="https://player.vimeo.com/video/139554482?title=0&byline=0&portrait=0&badge=0&autoplay=1&background=1&loop=1" width="400" height="230" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
            </div>
        </div>
    </div>