Hi there,
the Content / No Sidebar option – simply removes the sidebar from the blog and archives. It doesn’t have any other impact on the customizer settings such as padding.
So what i can see is first this CSS:
#content.site-content {
padding: 0;
}
Which is removing any content padding the Customizer would apply – this is across the site.
And then this CSS:
.entry-content {
padding: 0 10px;
}
Which is adding 10px left/right padding back to entry-content …. which only applies to the single posts as the class doesn’t exist on blog / archives.
In addition there are several other CSS styles being applied to affect padding – can’t see where they all come from due to the cache.
So first things would be to clear and disable any caches / critical CSS – to see if they are mixing up the order. And then its a case of working through your CSS to see what is affecting what…