Full screen "gvim" window located above other, but
Alt+Space -> "More actions" -> "Keep above others"
flag does not set.

Reproducible: Always

Steps to Reproduce:
1. Open "System settings" and "Chromium"
    on screen 1.
2. Run "gvim" on screen 1.
3. Run
    wmctrl \
         -r GVIM \
         -b add,fullscreen
    for make "gvim" window full screen
    on screen 1
    (or press "kwin" hot key for make current
    window full screen).
4. On screen 2 open:
    "kate", "gedit"
5. Use Alt+Tab for switch
    "kate" -> "gedit",
    "gedit" -> "kate"
    on screen 2.
6. Use Alt+Tab for switch
    "kate" (screen 2) -> "Chromium" (screen 1).
Actual Results:  
"Chromium" (screen 1) window got focus, but
stay invisible.
"gvim" (screen 1) window is visible, but
do not have focus.

7. Press Alt-Tab for switch
     "Chromium" -> "System settings"
    on screen 1.
Result: "System settings" (screen 1) window
has focus, but
only "gvim" (screen 1) window is visible on screen 1.

Expected Results:  
6. "Chromium" (screen 1) window must be
     visible and must have focus.
     "gvim" (screen 1) full screen window
     must be invisible.
7. "System settings" (screen 1) window must be
     visible and must have focus.
     "gvim" (screen 1) full screen window
     must be invisible.


This bug repeatable for any applications,
not just for "kate", "gedit", "gvim",
"Chromium" and "System settings".

This bug repeatable, when we
use "kwin" hot key or other utility
for make window full screen.