Banner image not appearing

Hello. I’m having difficulty getting an uploaded banner image to appear. The file uploads and saves, but doesn’t appear on the site.

Alternately, if I try to upload the same image as a “header” (which I don’t want — I want it as my banner image), it appears, but is truncated from the instructed size (1060 x 250). It is cropping it shorter than 250px and doubling it horizontally.

I assume the recommended 1060 x 250 dimension is intended for the banner image, not the header image (although 1060 x 250 is the dimensions it asks for).

Not sure what I am doing incorrectly, or where my confusion lies.

Thanks in advance for any help.