IPv6 not working (Windows 10)

[Lichtenshtein]

Here as we tested, sometimes it shows IPv6 "Supported", and sometimes "Not supported".
IPv6 is supported by Chromium all the time, but it has a fallback mechanism.
When certain timeout is reached, Chromium will fallback to use Ipv4.
In brief, Chromium uses IPv6 only when it is fast enough, otherwise it uses IPv4 instead.
You can ping v6.ipv6-test.com(their IPv6 test server), you may find out it is not very stable.

Seams like because of that fallback mechanism it becomes impossible for me to use IPv6 sites at all. Because Teredo servers are much slower than if i use the native IPv4.    But it's strange because as i said in Windows 7 all worked fine, and now i can't even open ipv6.google.com in CentBrowser. 
I set IPv6 priority higher than IPv4 in Windows. The idea is that if a site (for example google, wikipedia, yandex) has an IPv6 version it redirects me to it automaticaly even if i open an IPv4 verison. This works in Firefox, but not working at all in CentBrowser.
Can you make it possible to cheat that "fallback mechanism" to give IPv6 traffic a higher priority in Cent? As an option in browser settings of course.

//UPD. I forgot to mention that IPv6 is a good method to bypass goverment censorship due to that many ISPs forget to block IPv6 versions of sites because they are not so common.