Comic Press Width Change?

I am working on a new webcomic and putting together the site.

However I am having an issue with Comicpress with showing the full sized image of the comic.

https://www.nonchalantsquawk.com/

The comics are going to be 1500 pixels in width. I select the option to show full size, but it is not showing full size.

The direct comic link is https://www.nonchalantsquawk.com/wp-content/uploads/2014/10/sap.png for the full size.

I can’t seem to find how to fix this anywhere. Any advice would be greatly appreciated.