Sidebar flow

I am having issues with the flow of the sidebar on the site I am designing for myself using the free version of the Blackbird Theme.

My site: https://www.tesolgames.com

Some pages the sidebar flows properly (ie: to the right of the page)
Works:
https://www.tesolgames.com/about-us/ (this is a page)
https://www.tesolgames.com/category/students/ (this is a post)

Some pages the sidebar fall below main content.
Doesn’t work:
https://www.tesolgames.com/teaching-organizations/ (this is a page)
https://www.tesolgames.com/researchers/ (this is a page)

I have tried many different ‘fixes’ for this with no luck.

I have disabled all plugins…the issue still exists.

I have checked in Safari, Chrome, Firefox and Opera and the issue is in all browsers.

What adds to my confusion/frustration is that when I am logged in as an Admin (I have the Admin bar at the top of my browser), the flow issue seems to disappear..ie: everything looks fine in the browser I am working in, But if I load the problem pages in another browser the problem still exists.

Any suggestions for possible fixes? Any ideas as to what may be causing the problem?

Thanks to any and all for their advice.