Just reproduced in a clean install in a VM to rule out configuration
cruft on my laptop. With plasma-workspace 5.18.5 it doesn't appear, on
5.18.8 it does, as shown in the attached video.
** Attachment added: "kubuntu-screen-locking-after-upgrade.webm"
https://bugs.launchpad.net/ubuntu/+source
*** This bug is a duplicate of bug 1946177 ***
https://bugs.launchpad.net/bugs/1946177
Thank you for taking the time to report this crash and helping to make
this software better. This particular crash has already been reported
and is a duplicate of bug #1946177, so is being marked as such.
