SUMMARY Demonstrative video: https://www.youtube.com/watch?v=oUvqM4qPeHc In almost every KCM out there, the settings need to be applied separately after changing the values. The bluetooth kcm is an exception that it accepts the changes automatically as soon as they're made. For consistency's sake, add an apply button SOFTWARE/OS VERSIONS Linux: Arch Linux KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.112.0 Qt Version: 5.15.11
Right, this KCM is instant-apply for technical reasons. As such, the lack of an Apply button considered intentional. There are multiple other instant-apply KCMs that also lack Apply buttons.