I created a box with an image I want to use as the background on all of my site’s pages. It shows up OK on all pages except that when I change the height to make it take up the full page, it changes to that height on all pages (for each different device). This causes a lot of problems when the pages are different lengths. The only thing I can think of to fix this is to place a unique copy of it on every page instead of turning on “show on all pages”. Is there something I’m missing? Please see the link for my current settings.
I think it would be best @chile9 to use the setting Page / Background / Content / Custom Pattern and follow the prompts to upload your image and use it as the page background.
I have had this same issue myself.
I look forward to trying your solution!