STEPS TO REPRODUCE
1. Boot labtop with external monitor attached. (Labtop is configured to use external display in before previous shutdown) . Monitor is attached via display port.
1. External monitor shows normal loging screen. After successful login, there are no configured panels, widgets, launcher or desktop. Some applications from previous boot is running but kde activities, panels, desktops are not available. Applications can be searched via alt-space
Normal configured desktop enviroment must show. The bug can be circumvent by disconneting external monitor, rebooting labtop after login and seeing the normal desktop environment connection external monitor to labtop again and sending video to external monitor works
KDE Plasma Version: 5.18.3
QT Version : 5.14.1
KDE Frameworks Version: 5.68.0
Kernel 4.19.113-1-Manjaro 64 bit
Even if the method used described above to circumvent the bug, in normal usage, there are case where while switching activities, external monitor loses video and reports there is no signal. After a while video signal comes back and activities are displayed. I am using around 10 activies each one of them is loaded my open documents.
*** This bug has been marked as a duplicate of bug 391531 ***
*** This bug has been marked as a duplicate of bug 371717 ***
*** This bug has been marked as a duplicate of bug 353975 ***