iframe height of h5p is set to 1px in Safari

Unfortunately there's a problem with the height of the iframe in Safari. In Chrome the element is exactly the height of the h5p content. In Safari the height is 1px. I can change the height by css, but the height is different for each h5p widget. Does someone use h5p and recognize this problem?

I use the h5p plugin on wordpress.

I allready searched a lot on this forum and tried this, but it doesn't solve the problem.

var resizeIframe = function() {

          H5P.jQuery(window).trigger('resize');

        }

        window.onload = function() {

          setTimeout(resizeIframe, 3000);

        }