Hey guys I need help with settings or maybe it's bug.
I use multple desktops . 3 x 3 layout on two monitors.
After update I'm exepriencing problems with all window of same application not showing in task bar.
I'm not using GROUP windows feature and on ALT+TAB I can see the windows to switch to ... but on taskbar only one application window is shown..
Application in question is IntelliJ 2017 and IntelliJ 2016 ... I've tested with different versions of IntelliJ to see if maybe something broke after IntelliJ version, but I found out that after Kubuntu update (of plasma) this started to happen.

I've got screen-shot of my screen showing 2 application windows and only one apears on task bar, but cannot upload it here ..

My setup:
2 monitors (one 30 " one 27" )
Kubuntu 16.04
KDE plasma 5.5.5
QT version 5.5.1

OS type 64