I wonder whether the following is due to a change in the gentoo packaging of konqueror, or due to a change upstream.
Since I upgraded to kde-apps/konqueror-17.08.3, I cannot open a new instance (new window) of konqueror unless I specifically go to File > New Window.
For example, clicking on the 'konqueror' menu item in the k-menu on in the shortcut I placed in my toolback or calling 'konqueror' from the kicker, always focus a previously activated konqueror session.
It is a very annoying regression, and I cannot see a way to change this new behaviour.
Same for other single-instance applications like ktorrent. So, certainly not a (downstream) bug, and probably regarded as a feature rather than a bug in general.
It seems you can change behaviour of konqueror.desktop by making it execute `konqueror about:blank` rather than without URL argument.