I am noticing when I go to customize in any of my themes ie gridmarket, when choose Background Image, i can choose a background image and then save the changes. However the next time I go to customize (ie close the window then come back to it), even though the background image is appearing in the theme, the control doesn't show the image, so the option to remove the image isn't present. Attached is a screen shot.
Any ideas why this may be occurring? I didn't notice it till recently and wondering if other people are having the same issue, wondering if its a Wordpress 4 issue.