Thank you for the details.
The second page which was edited in Cornerstone using the page background image. You might have added this in the page itself. Please check your product page settings. To know more about page settings which is where you can find the page background, please check this out:
If nothing is working, would you mind providing us the url of your site with login credentials so we can take a closer look?
To do this, you can create a secure note with the following info:
– Link to your site
– WordPress Admin username / password
To know how to create a secure note, please check this out: https://theme.co/apex/forum/t/how-to-get-support/288