we have recently had the need to utilise the category banner image in Hotcakes but ran into an issue so an writing this here in the hopes that it may help someone else in the future.
In catalog > categories there is an option to add both an icon image and a banner image to each category.
if you use the drag and drop method of selecting an image from your local machine then the site will take you image and create an image in both the Hotcakes\Data\categorybanners and the Hotcakes\Data\categoryicons folders and will create the link for the icon to display but not the banner.
To successfully add separate images for the icon and the banner you must use the browse button to select the required banner image from your local machine and not use the drag and drop method.