Good morning,
OK, I just went through my entire media library and I do not have a 300×300 sized version of that photo coming up. I see it in the link you provided, but that is not what I am using for the featured (slider) image. The picture I am talking about is this one: DSC_6549aa.jpg and it is 2048 × 1365 and I use the fix image option on each image I upload ever since I first heard about it and it still comes out distorted and stretched on the slider, but looks perfectly fine on the target page.