I would just like to know if this is nvidia, system or KDE issue. Note that i can not move the screen back to primary monitor even using KDE daemon shortcut for switching display (Meta+P). The shortcut otherwise works fine when i do normal work.
Applications shouldn't have the power to enable or disable displays at will and without user permission. Certain programs are therefore easily overriding my system settings.


Games:
- Battle for Wesnoth (from repo),
- Assault cube (from repo),
- World of Padman (not in repos, version 1.6 downloaded from website)

When running these in full screen, the primary display (LG VGA monitor) turns off and the disabled display (LG HD TV) turns on. Game is then properly displayed on the new display instead of on computer monitor.

Secondary display is turned off in system settings as well as in Nvidia settings.
Screenshots of nvidia and system settings (i couldn't find a way to attach them so here is the link to google drive):
https://drive.google.com/open?id=1U5v8P ... 7P6U7ga0xH

edit pasteboard images:
System settings
https://pasteboard.co/Ic1ROPe.png
Nvidia settings
https://pasteboard.co/Ic1Sb3r.png

1)
Hardware is old:
Single core AMD Athlon 64 Processor 3800+
RAM: 4 GB RAM
Nvidia GT 730 with installed nvidia drivers version: 390.116
default screen resolution: 1280x1024

System: Kubuntu 18.04.2 LTS
KDE plasma: 5.12.7
KDE Frameworks: 5.44.0
Qt version: 5.9.5
Kernel Version: 4.15.0-47-generic
OS Type: 64 bit

2)
Multiple packages are affected as outlined above. The applications do not crash, however i can not get them to display on proper monitor and they are overriding system settings.

3)
The games should run in full screen on the enabled monitor.

4)
Games instead turn off the primary monitor and enable the disabled monitor and run there (secondary display).