SUMMARY
I'm unable to use virt-manager and virtualizing Windows / other KDE Plasma and copying or pasting text. If I want to use clipboard, I have to close virt-manager or "hope" that next copy / past won't freeze keyboard. I had to jump to GNOME in order to do some virtualization... And I'd love to use Plasma ;-)

STEPS TO REPRODUCE
1. install Debian Testing with KDE Plasma 5.14
2. install virt-manager and run Windows with Spice drivers of Ubuntu with Plasma
3. copy and paste text withing host or between host and VM (guest) or just in VM (guest)
4. keyboard freeze randomly stops working for approx 60 seconds when copy / past (it's random, sometime it's OK, sometime not)

OBSERVED RESULT
typing on keyboard does nothing

EXPECTED RESULT
keyboard should work

SOFTWARE VERSIONS
plasmashell --version
plasmashell 5.14.5

dpkg --list | grep plasma
ii  kde-plasma-desktop                5:102        amd64  KDE Plasma Desktop and minimal set of applications
ii  kdeplasma-addons-data             4:5.14.5-1   all    locale files for kdeplasma-addons
ii  libkdeclarative5                  4:4.14.38-3  amd64  declarative library for plasma
ii  libkf5plasma5:amd64               5.54.0-1     amd64  Plasma Runtime components
ii  libkf5plasmaquick5:amd64          5.54.0-1     amd64  Plasma Runtime components
ii  libplasma-geolocation-interface5  4:5.14.5-1   amd64  Plasma Workspace for KF5 library
ii  libplasma3                        4:4.14.38-3  amd64  Plasma Library for the KDE Platform
ii  plasma-dataengines-addons         4:5.14.5-1   amd64  additional data engines for Plasma
ii  plasma-desktop                    4:5.14.5-1   amd64  Tools and widgets for the desktop
ii  plasma-desktop-data               4:5.14.5-1   all    Tools and widgets for the desktop data files
ii  plasma-discover                   5.14.5-1     amd64  Discover software management suite
ii  plasma-discover-common            5.14.5-1     all    Discover software manager suite (common data files)
ii  plasma-framework                  5.54.0-1     amd64  Plasma Runtime components
ii  plasma-integration                5.14.5-1     amd64  Qt Platform Theme integration plugins for KDE Plasma
ii  plasma-nm                         4:5.14.5-1   amd64  Plasma5 networkmanager library.
ii  plasma-pa                         4:5.14.5-1   amd64  Plasma 5 Volume controller
ii  plasma-runners-addons             4:5.14.5-1   amd64  additional runners for Plasma 5 and Krunner
ii  plasma-scriptengine-javascript    4:17.08.3-2  amd64  JavaScript script engine for Plasma
ii  plasma-wallpapers-addons          4:5.14.5-1   amd64  additional wallpaper plugins for Plasma 5
ii  plasma-widgets-addons             4:5.14.5-1   amd64  additional widgets for Plasma 5
ii  plasma-workspace                  4:5.14.5-1   amd64  Plasma Workspace for KF5