Below is a screen shot of what I'm calling "lost shading". By moving pages around, possibly with incorrect shuffling settings, I now have half a page shaded and the other pure white.
I can't drag/expand the shaded side across the spread. I can't copy and paste it from another spread. Something is wrong with the page itself since it resists any approach I've tried.
Thanks for the advice.
Some pages look like this:
Europe, Middle East and Africa