SUMMARY kdeconnect running in arch linux on plasma-desktop will not connect to Android phones STEPS TO REPRODUCE 1. Start kdeconnect on Pixel 4XL phone and on plasma desktop 2. kdeconnect shows no devices available on either laptop or phone 3. OBSERVED RESULT No connections or new pairing possible EXPECTED RESULT Paring should be allowed and connection between laptop and phone allowed SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: kdeconnect 21.04.3-1 plasma-desktop (available in About System) KDE Plasma Version: 5.22.4-1 KDE Frameworks Version: 5.84.0-1 Qt Version: 5.15.2+kde+r211-1 ADDITIONAL INFORMATION In the log journal there are multiple log entries with: Aug 07 12:43:30 lenovo1 kdeconnect-app[4768]: qrc:/kdeconnect/qml/PluginChecker.qml:20:47: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... } This looks related to an issue with QT5 - eg see https://stackoverflow.com/questions/62297192/qml-connections-implicitly-defined-onfoo-properties-in-connections-are-deprecat and on the laptop and my other systems I now have qt5-base 5.15.2+kde+r211-1 so I wonder if the kdeconnect code was not updated to include the change in qml connections in QT5?
I have found the solution to this issue. The problem was that the nftables firewall did not flush the firewall rules when the nftables service was stopped. A recent change to nft meant that previous behaviour that stopping the nftables service would flush the ruleset was changed, and it is now necessary to manually flush the ruleset after stopping the firewall. Once the nft rules are flushed kdeconnect works perfectly. Additionally when I added the port range 1714-1764 to the nftables rules for udp and tcp, and restarted the nftables firewall kdeconnect continues to work perfectly with the firewall running. So I will close this bug now.