wifi network losses internet connection when openvpn is used.

after connecting to vpn server ***routing table*** is altered and wifi entries
appears multiple time. 

after connection to vpn couple of time internet is works, but at some moment it
drops. after that only physical restart is helpful to restore connection, or
restarting wireless router. when internet is gone, its still possible to
connect local addresses inside network, like wifi router.

for connecting to vpn is used kde networkmanager. 

itself restarting networkmanager with systemctl restart NetworkManager
does restore internet connection, but without any further manipulation its lost
after couple of seconds.