openvpn don't switch to fallback

[MAIRIEN Anthony]

On Ubuntu 20.04.3 LTS (5.11.0-34-generic #36~20.04.1-Ubuntu) without any extra packages installed, the following event occured :

In the OpenVPN client config file, we have two servers (remote foo.bar 1194 udp, remote foo2.bar 1194 udp). We imported this config file in the Network-Manager's GUI and then we started the OpenVPN client (again via the GUI).

When connected (from an external network), we started a simple ping to check the connectivity to the remote network. Then, we completely disconnected the first remote server (foo.bar), and logically the VPN client should have reconnected to the "foo2.bar" server, AKA the fallback server.

But, after more than 10 minutes, the connection is still non-reestablished (although the default value of the connect-timeout parameter is 120s). The GUI was acting like the connection is still up, although the remote VPN network was unreachable. We had to manually turn off the VPN client on the GUI and turn on again to reconnect (it took a very long time because it first tried to connect to the offline VPN server).

If we launch the VPN client in command line, the fail-over works perfectly. The command used in CLI is simply : `sudo openvpn config.ovpn`

The version of the packages are the following:
network-manager/focal-updates,now 1.22.10-1ubuntu2.2 amd64
network-manager-openvpn-gnome/focal,now 1.8.12-1 amd64
network-manager-openvpn/focal,now 1.8.12-1 amd64
openvpn/focal-updates,now 2.4.7-1ubuntu2.20.04.3 amd64

Thank's in advance for lookin into this!

Kind regards,
Anthony Mairien