Edge Browser and Blog Layout Preview Image

Hello,

For some reason, only in the Edge browser, the preview images for blog posts are being pulled from a 180x180px image and stretched to 300px. But using other browsers, the clear and correct 300x300px images are being displayed.

I tried adding code like the below in various combinations but nothing seemed to work.

.blog .blog-meta, .blog .small-preview {
height: 300px;
width: 300px;
}

.small-preview {
height: 300px;
width: 300px;
}

img.attachment-square.size-square.wp-post-image {
width: 300px;
height: 300px;
}

Site: http://www.happinessplunge.com/blog
Edge vs IE side-by-side: http://imgur.com/a/YajLr

Yes, I’ve cleared cache each time I’ve made CSS changes to make sure changes would be reflected.

Any ideas or thoughts? Thanks!