SUMMARY:

    A newly installed KVM guest sleeps and it is not possible to wake it.

STEPS TO REPRODUCE:

    Install a new Neon Testing

    Log in and update with "pkcon refresh; pkcon update"

    Go away while it is thinking, drink tea, come back later and try to wake the system

    (It does not seem to matter whether you are using QXL or Virtio video or whether
    you select an X11 or Wayland session.)

OBSERVED RESULTS:

    You don't get a response. All seems dead, even Ctrl-Alt-F2 (via Send Key) does not
    give a command line logon option.

    Does not visibly react to "Reboot" or "Close Down" from the Virtual Machine Manager,
    you have to "Force Off".

EXPECTED RESULTS:

    You should get something...

SOFTWARE/OS VERSIONS

    Neon Testing (from neon-testing-20230329-1528.iso)

    Plasma: 5.27.3
    Frameworks: 5.105.0
    Qt: 5.15.8

ADDITIONAL INFORMATION

    If you install/enable sshd on the guest and connect, you see that the ssh connection
    drops. If you try to wake the system (by typing "things" into the blanked screen)
    the system silently wakes and you can connect again with ssh and close the system
    down gently. You do not get any response on the screen.

    It does not seem related to the screen saver, that can be disabled and the issue
    persists. Watching Journalctl shows that the system is sleeps when the screen blanks
    (and the ssh connection drops). It seems related to Power Management and the
    "Suspend Session":

        System Settings > Power Management > Energy Saving

    has "Suspend Session" enabled with a 15 minute timeout. Disable that and the issue goes away.

    It could be, that if you are drinking tea and the system goes to sleep, that this *just* qualifies
    as a Plasma 15 minute issue 8-]

    Probable that the screen freezing is not dependent on the "pkcon update" but that seems to
    raise the stakes.