Problem with the featured images in IExplorer

Good morning,
I’ve just changed my wordpress theme, now i’m using MH Magazine lite. In the homepage, when you are using firefox or chrome everything it’s correct but with Internet Explorer there are not thumbnails, all the featured images are shown with their real sizes, on the slider and on the custom post widget. What is the solution? My web is https://hoyciclismo.com

Thanks for helping