Within the last several days an update has caused the the desktop folder (folder view mode) to become unresponsive. The desktop icons do not respond to mouse clicks, selection, hover or even keyboard shortcuts. Everything else in KDE operates normally. I found a workaround that requires selecting "Layout mode as Desktop" and then re-selecting "Layout mode mode as Folder View". This restores correct operation. However, after system reboot, the problem returns. I am using Kubuntu 18.04.