CUNY Academic Commons

I thought that was the problem too but I have "content on left" selected. I really have no other idea why it is not showing up.

Looking more closely at https://psrg.commons.gc.cuny.edu/, it looks like the following is happening:

1. The site is configured so that the "front page" is pinned to "The Public Space Research Group" page. See https://psrg.commons.gc.cuny.edu/wp-admin/options-reading.php
2. That page uses Twenty Eleven's "Default Template" for pages, which doesn't show a sidebar. See https://psrg.commons.gc.cuny.edu/wp-admin/post.php?post=38&action=edit, the "Page Attributes" section at the right. You can select the 'Sidebar Template' to change this behavior.