I’m not sure what you mean by “middle-mouse-button-scroll”, in the context of “uncommon modifications”. My middle mouse button scrolls the screen up and down when I scroll it.
Perhaps this is the difference in our Chrome experiences then, a Windows vs Mac thing? And the issue you’re reporting (middle clicking not working after the first middle click) sounds like the IE11 bug mentioned above, which HAS been addressed as something that needs to be looked at.
