osseo
Let me explain a bit here:
This page: https://www.district279.org/pre-k is assigned with template style: ja_university_t3 - enroll-pages which is using layout 'right-sidebar-copy' in local folder
/templates/ja_university_t3/local/tpls/right-sidebar-copy.php
I check this file and see that it's loading this block for mainbody:
<?php $this->loadBlock('mainbody-content-right') ?>
but you didn't override this block yet so you can check this file in this folder:
/templates/ja_university_t3/tpls/blocks/mainbody-content-right.php
If you open this file, you can see that there are some conditions to load associated layout for the main content. On above page, you show modules in right sidebar only so this layout file will be loaded:
/templates/ja_university_t3/tpls/blocks/mainbody/one-sidebar-right.php
So you will need to edit this file as my above suggestion.