Created attachment 159487 [details] Screenshot In Plasma 5 there is a Settings button on popups to go directly to configure the notification type. See screenshot.
Works for me with that specific notification, as well as others that have their metadata properly set. How is plasma-nm packaged? Can you verify that its networkmanagement.notifyrc file got installed?
/usr/share/knotifications6/networkmanagement.notifyrc is installed. Contents here to avoid mess in comments: https://pastes.dev/QLWS3StCaE
Weird, then it should be working. Not sure what might be broken for you. Do you see configure buttons on *any* notifications* that used to have them for you in Plasma 5?
Are you still able to reproduce this with today's git master?
"notify-send foo bar -h string:desktop-entry:firefox" works fine and shows a Settings button so I'll close this. If I notice it re-occur I'll reopen or open a new report.