Issue with IE 11 and One Column page

Hello,
I’m hoping someone can help me. The person who usually assists me is not able to currently. I have a site https://www.TheMainStreetMouse.com we have most pages set to have both the left and right sidebar. There are select pages that only have the one column templates and it works fine in chrome and firefox, but not in IE 11. It did work so I’m not sure why it’s not anymore. If you look at either of these pages:

https://www.themainstreetmouse.com/tmsm-merchandise/
https://www.themainstreetmouse.com/tmsm-trivia-channel/

You will see the column just lines up to the left in IE 11 and leaves half the area blank. If you look at them in chrome they are displayed how I want them. I know there are issues with IE and how it displays the CSS, just not sure where or how to fix this so IE 11 behaves like other browsers.

Thank you,
Scott