Created attachment 782423 [details]
edit-wifi

Sometimes plasma-nm loses all connection info.
When I click "connect" to WiFi network a window with empty fields is displayed
(edit-wifi attachment), but when I click on "Edit connections" some fields are
filed (connections.png attachment) without password.
For other WiFi connections(with password only) plasma-nm asks for password but
is not able to connect.
All passwords are stored in kwallet.
I can't connect to other wired networks too. Click on "connect" does nothing.

Plasma network manager loses all connection info and passwords.

Command:
$sudo systemctl restart network NetworkManager
or restart of computer sometimes resolves the problem
(connection_info_after_restart_services.png attachment)