My understanding was that bootstrap 3.xx supported IE8. When you to the bootstrap's navbar example page and switch to IE's document mode to version 8. The navigation bar displays as if it's displaying in a mobile device or small screen at all times.
Here is an image
I had this problem with a page I started developing and found people suggesting making sure to use Doctype which i was or using the non-minified version of bootstrap css which i tried without changes, then i noticed the sample page was doing the same, so the main question really is is IE 8 just not supported anymore?