This is not a recent discovery, it has been known for a long time. Disabling IPv6 is the incorrect way to handle it. The problem occurs because of VPN providers not supporting IPv6 Internet access into the VPN. If the host already has IPv6 access, as is increasingly common, traffic to sites like Google, Facebook, Yahoo, Netflix, Akamai, Linkedin will bypass the VPN and go out on the IPv6 access.
The story here is that VPN providers need to support IPv6 not that IPv6 should be disabled on the host. The VPN should allow IPv6 or IPv4 for the tunnel transport and IPv6 and IPv4 for the encapsulated user traffic. When the VPN is brought up both IPv6 and IPv4 default routes can be pointed into the VPN and the DNS servers should be assigned by the VPN provider.
Biting the hand that feeds IT
