I update from automatic update from Plasma 5.15 to 5.16. Plasma 5.16 do not work with numpad keyboard to Logitech K310. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Manjaro KDE Plasma Version: 5.16.2 KDE Frameworks Version: 5.59.0 Qt Version:5.13.0 ADDITIONAL INFORMATION I write to manjaro forum. But do not help me.
It helped me to restore the settings about something has been damaged.