This is something that will be adjusted in the next update. Featured Posts and pages show up with a 300px width by default, and there needs to be an override for the homepage so it will be as wide as the widget it’s added in.
Here is the exact part that is adding the width on line 1468 –
.home-feature-bg-alt .featuredpage .page,
.home-feature-bg-alt .featuredpost .post {
float: left;
margin: 0;
overflow: hidden;
padding: 0 0 5px;
width: 300px;
}