Users running a KDE (Plasma 5) session are not visible in the output of "who"
or "last". Same problem for IceWM session on a KDE installed system. Only open
consoles (within the KDE session or in a text terminal) are listed by who/last.

In a GNOME installation of 42.2 the error doesn't occur.

The error was observed for the first time in Leap 42.1, persists in 42.2 and
Tumbleweed but does not exist in openSUSE 13.2.

Steps to reproduce:
Login user A to a KDE session but do not open any console in this session.
Switch to text terminal and login as user B. Check for running session of user
A (who / last A).