IPv6 not working (Windows 10)

[Lichtenshtein]

Hi. After migrating from Windows 7 to Windows 10 i found that IPv6 is not working on Chrome, CentBrowser in particular. IPv6 tests fail, IPv6 sites are not working on exact same version of browser but on another OS. For example in Firefox it works more or less normally, you can see the screenshots below. Is there a way you can fix this in CentBrowser? Thanks.

[Admini]

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.

[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.

[Admini]

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.

There are no options/flags to force using IPv6.
Or we can add a command line to implement this feature.
Have you tried unchecking the "TCP/IPv4" option in your network connection properties?

[Lichtenshtein]

Have you tried unchecking the "TCP/IPv4" option in your network connection properties?

Yes  But that was not a good idea, because Teredo protocol uses IPv4 to work.

Or we can add a command line to implement this feature.

That would be a great feature if you implement this.
Thanks for reply.

[Admini]

We have added a command line "--cb-ipv6-fallback-timeout-ms" to customize the fallback timeout of IPv6 probe.
You use it in "startup command line" option like this:
--cb-ipv6-fallback-timeout-ms=5000