Ubuntu – free VPN service that works on Ubuntu?

See the options it has. openconnect --help:

-u,--user=NAME

Set login username to NAME

--passwd-on-stdin

Read password from standard input

--reconnect-timeout

Keep reconnect attempts until so many seconds have elapsed. 
The default timeout is 300 seconds, which means that openconnect 
can recover VPN connection after a temporary network 
downtime of 300 seconds.

it also supports a

--config=CONFIGFILE

There are several scripts on-line you can adapt to your situation.

I performed a:

sudo apt install network-manager-openconnect-gnome

Then I setup the VPN details via the GUI. When I connect now via the GUI, it is working and there is communication.

I still need to investigate what is happening differently, but this might help in the meantime.