Header Images not appearing in Maintenance Mode

Hello, 

Our images for the ‘Rotating Header’ are not appearing on the site. When I inspect the page, I can see the browser attempting to load/rotate the images, but returning a 503 error. It seems like the images cannot be rendered because the site is in maintenace mode, and therefore the images are not publically accessible. 

Have you heard of this issue before and do you expect it to be resolved when I turn off maintenace mode? If so, I will wait to design images until the rest of the site is ready to be public.

Thanks!