This is a minor issue. When pressing the screenlock keyboard shortcut, normally Ctrl+L the lockscreen appears for a few milliseconds and afterwards disappears again. I think this is the default setting. It would be better to show the lockscreen for 2 seconds and then fade out and turn off the screen.
This isn't the default behavior of the lock screen on Fedora or other distributions I have recently used. Can you check this setting: System Settings -> Power Management -> Suspend Session -> Turn off screen What's that set to?
🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME. For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging. Thank you for helping us make KDE software even better for everyone!
🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.