Hi Andrii,
Thanks for this suggestion. I had a look this, but I am a bit puzzled:
1. I have a installed the plugin “WP Media Gallery” added a gallery with the photos. These all have captions.
2. On my homepage, for ‘Choose header for this page’ I’ve selected Background Slider
3. Here is where the problem is: for “Background Slider/Image Source of Images” i select “WP Media Gallery” and update the page it remains on none. It says “Images from the WP Media Gallery attached to this post/page will be used.” I am not sure how to attached the “WP Media Gallery” to the page? Click on “Add Media” for the page doesn’t include my new “WP Media Gallery” images.
Could you point me in the right direction?