Clipboard freezes when copy to/from KVM VM

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changing target to Kubuntu

Has there been any progress with this?

I am having a similar issue with Manjaro KDE as the host with Kernel 5.3.11 64 bit on an Intel i7-4790k with security mitigations disabled with mitigations=off as a grub option. I have had the issue copying text from a larger editor like Atom or VSCode (snap install code) to Konsole or to another file. This may actually causes the receiving app to freeze, like the console not to accept new text.

My guest is a Kubuntu 18.04.3 installation also with mitigations=off. I tried installing a newer kernel using Ukuu 5.3.12 which may have reduced the frequency?? I am not sure, but it did not solve the issue.

The guest KDE interface also seems to freeze as well. The taskbar that is typically at the bottom of the screen seems to become unresponsive. However, functionality like alt-tab seems to work. If I copy some other text or paste into something else, Konsole may unfreeze.

The copy and paste issue actually seems to break into the host KDE Manjaro system where KDE refuses to paste new text if I use VMs alot (open and stopping different vms for example). I was unable to reproduce this part of the issue, but it did happen.

Has there been any progress with this?

Cut and paste is broken within the virtual machine. This makes working with it extremely difficult.

Within the virtual machine, copy and paste sometimes works the first time. Thereafter copy and paste sometimes locks up the the application, and more often than not, the menu bar is frozen so that I cannot open other applications.

The clipboard does not show the latest item copied. Multiple attempts to copy are ignored.

The one place that copy and paste works is solely within Kate, but not between Kate and anything else.

Both Ubuntu host and virtual machine are:
Ubuntu 18.04 (bionic)
5.3.0-51-generic (#44~18.04.2-Ubuntu SMP Thu Apr 23 14:27:18 UTC 2020)

Both KDE installations are:
KDE Plasma Version: 5.12.9
KDE Frameworks Version: 5.44.0
Qt Version: 5.9.5