Timeouts and bad performance on NextDNS with IPv6

Hello,

I find myself getting more and more timeouts lately, the frequency increasing every day. When I don't get a timeout, it does still take ages for anything to happen. Some domains will consistently time out whenever I connect, and are unreachable.

I did find that the issue is exclusive to the combination of NextDNS and IPv6 – either disabling IPv6 or switching to a different DNS immediately makes the timeouts stop and drastically improves performance.

Here is my diag: https://nextdns.io/diag/d8978320-4a3e-11ee-833f-b5a30793dcb1

And, of course, some example domains that showcase the issues:

• nvidia.com (guaranteed timeout)
• wizards.com (guaranteed timeout)
• youtube.com (inconsistent performance with occasional timeouts)
• ffxiv-login.square-enix.com (always slow within the FFXIV launcher)

Until this gets fixed, I suppose I'll just have to disable IPv6 for a while as a workaround.