Password with non-ascii characters
I made the mistake of using the letter U+00E4, ä, c3 a4, LATIN SMALL LETTER A WITH DIAERESIS
in my password and after that opening a VPN connection with openconnect v8.02 fails with a simple "Login Failed." response.
After changing my password to not contain the letter ä, the VPN connection works again.
This is a company VPN so can't really post all the details here, but I ran openconnect -v --printcookie --dump-http-traffic
and from the output it looks like this is related to the HTTP request containing an UTF-8 encoded XML but the Content-Type is advertised as "application/x-www-form-urlencoded" which does not define the charset.