Issues with background images

I want to add a custom header image to my wordpress blog. But even if everything goes ok with uploading, I made it more than the minimum image scale. And it shows as current image. I keep getting a blank header with only a plain color header.

Not sure if there is something else I need to enable somewhere else.

I include an image showing up the header here:
https://i.imgur.com/c0jZZI4.png

Thanks.