This thread is resolved. Here is a description of the problem and solution.
Problem:
The issue here is that the user's theme is not allowing the full width section with Layouts
Solution:
In this user's case the theme is setting the container with a fixed width. However bootstrap using the a fullwidth container to provide the full width background.
For this user they needed assistance from their theme support as a fixed width was being used for their container class.
This support ticket is created 5 years, 10 months ago. There's a good chance that you are reading advice that it now obsolete.
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Our plugin uses the .container class to determine the full width of a div. In your theme the .container class has a fixed width of 1280px. Normally this would be set to 100% in bootstrap. Since this is the case of your theme then it wouldn't be possible to do this unless the container has a 100% width.
What you can do is to try using your page builder in a content template and create the fullwidth section, then add that content template to Layouts.
This may work in your case since the page builder might be using a different set of rules to do its fullwidth items.
I'll write to the Theme support asking them for a solution with this fixed width.
In any case, I think I'll be able to solve my problem with your solution.
I'll keep this ticket open until they answer me, but your work with me is done.