I have sky obviously and mine works fine with sky's ipv6 no problem.
Windows PowerShell
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PS C:\WINDOWS\system32> ping -6 google.com
Pinging google.com [2a00:1450:4009:801::200e] with 32 bytes of data:
Reply from 2a00:1450:4009:801::200e: time=9ms
Reply from 2a00:1450:4009:801::200e: time=9ms
Reply from 2a00:1450:4009:801::200e: time=10ms
Reply from 2a00:1450:4009:801::200e: time=9ms
Ping statistics for 2a00:1450:4009:801::200e:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 9ms, Maximum = 10ms, Average = 9ms
PS C:\WINDOWS\system32>