Yes, I can replicate that but ONLY if I move a page above the first page.
I think the first page is special in that it allows you to load multiple images into it to change all the other images in the widget etc.
So just leave the first page as is.

When I try to move an image to the 1st place or vice versa move the top image down, this text window dissappears and the preview fails/shows nothing. So I have to leave the 1st image in its place and never move it !
Yes but there's nothing stopping you dropping a new image onto the first page image to replace it