Question: Why IE11 Isn't Rendering Content as Expected?

I've been running into rendering issues with IE11 lately where html pages are not getting rendered as expected even though they show up fine in chrome, firefox, and safari. I'm still digging into this but it seems like it could be due to Internet Explorer being put into Enterprise Mode for "internal" web sites, (where "internal" means any web site matching the domain name of the organization--for example, *.somedomain.com). Has any one else come across this?

Enterprise Mode defaults to sending an IE8 user agent instead of an IE11 user agent and the meta tag that developers are encouraged to place in their html (<meta http-equiv="X-UA-Compatible" content="IE=edge">) is designed to tell the browser to use the best rendering mode of the browser. If IE11 sends an IE8 user agent because Enterprise Mode is enabled, does it then get rendered as IE8 even though the HTML could be standards compliant and rendered with IE11's standards compliant engine?