I am really frustrated with a problem that only occurs for me using Chrome and Lightning experience.

When I go to setup, and click on a "classic" setup page like "users", instead of opening it in the LEX iframe in setup, it opens a new browser tab with the setup page in it, but it is non-functional since it expects to be inside of an iframe.

I have tried removing cookies and plugins, but the problem keeps reoccuring and is driving me crazy!

Any help would be greatly appreciated, this has to have affected someone else out there besides me!