Widgets placed in After Content Featured widget area when using Essence Pro (tested in v1.5.1) appear in columns or other layouts depending on the number of widgets.
The line of code responsible for this is:
essence_do_widget( 'after-content-featured' );in Essence Pro’s functions.php (around L538).
If you are looking to have the widgets behave “normally” so they stack one below the other, replace the above line with:
genesis_widget_area(
'after-content-featured',
[
'before' => '<div id="after-content-featured" class="after-content-featured"><div class="wrap"><div class="widget-area">',
'after' => '</div></div></div>',
]
);