SUMMARY Some KCMs show an inline message after we apply a change, like a warning saying that the change will only be applied with newly started apps or after we restart plasma session. User is not aware of such messages if standalone KCMs are used and we click on "Ok" button to apply the changes because the KCMs closes immediately after click on such button. The following KCMs are affected: display configuration (only on X11 after display scale changing) cursors (only on Wayland) fonts and language (on both X11 and Wayland sessions) STEPS TO REPRODUCE 1. open standalone Fonts KCM 2. change any font setting and click on "Ok" button 3. OBSERVED RESULT KCM closes and user sees no message. If we click on "Apply" button instead, the KCM shows an inline message saying that some settings will only affect newly started apps. EXPECTED RESULT user is also aware of the message even if "Ok" button of the standalone KCM is clicked. Maybe the inline message can be shown as a Plasma notification. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.17.4 KDE Frameworks Version: 5.65.0 Qt Version: 5.14.0
After https://phabricator.kde.org/D29157 this issue only affects "Display Configuration" kcm launched via display configuration applet in systray.
Now that the KCM is almost always displayed inside system settings, this is probably not worth fixing, given that there is not really a good way to fix it in the first place.