Problem with header image blank\white

When I activate the “Arcade basic” template, the bachelors image is blank, although I set up an image with an exact size of 1800×1200.

Even if I try to apply the image that comes by default, the header stays blank.

Find out that if I zoom or zoom in the browser the image appears. That is, there seems to be some problem.

This is my site: https://goo.gl/Te9CRH

The page I need help with: [log in to see the link]