Maintenance mode only working for some pages, but not all??

I placed http://calhoun.yalecollege.yale.edu/ in maintenance mode now that the Grace Hopper site (http://gracehopper.yalecollege.yale.edu/) is live. The dean’s office would like to archive the site at some point, so until I have a firm decision on how they’re like to do this, we decided it would be best to use maintenance mode to avoid having students go to this site and get confused between this and the new Grace Hopper site.

However, when you go to the link you can still view the homepage instead of the maintenance mode page. Click on one of the menu items, such as ‘Student Organizations’ and you’ll see the maintenance mode message.

Click on other menu options such as Head’s of College Office, and then Head’s of College Staff, and you can still see content.

Am I mistaken that maintenance mode will redirect all pages on the site??