See this discussion:
https://www.msofficeforums.com/drawi...page-page.html. Basically, it's recommended that you don't insert images until you've finished the text editing, then insert them in order, starting from the front of the document.
As an interim measure, you could insert the images in-line with the text, then convert them to the square layout when you're finished the ext editing. Again, do the conversions starting from the front of the document.