Widget (Top Menu) is not updating with new image

I am having trouble updating the image for top menu widget, I have tried everything, including flushing the cache.

After removing the old image, I selected a new image, but even at this point, the preview is not updated with the newly selected image. I clicked ‘save’ anyway, but it doesn’t update. When I returned to the customise page and expanded on the option again, the old image is still showing in that particular widget. I even went around to the widget section to try to change the image, but to no avail.

Please help.