SUMMARY Network manager connection settings (see nm-settings manual) supports more entries than the network manager connection editor. When the connection editor finds some setting that it does not understand, it should leave it as is. Conversely, it removes it. This has unpleasant consequences, for instance when the mdns entry is removed from the [general] section of a connection configuration. STEPS TO REPRODUCE 1. Manually edit a nm-connection setting file to introduce an mdns entry 2. Modify the configuration of such connection with KDE OBSERVED RESULT The mdns entry is erased EXPECTED RESULT The mdns entry is not understood by the KDE connection editor and as such is left unaltered. SOFTWARE/OS VERSIONS Linux/KDE Plasma KDE Plasma Version: 5.18.5 KDE Frameworks Version: 5.68.0 Qt Version: 5.12.8
The only way how to fix this is to add mdns support, otherwise it will never be part of the configuration (parsed from DBus output we get from NM interface) and therefore updating the connection with new values will not contain it.
I started working on this, please see https://invent.kde.org/plasma/plasma-nm/-/merge_requests/23