Internet connecion sometimes really slow with IPV6


I have received a new box from my ISP (it is compatible with IPV6).
So I have activated the IPV6 filtering in Comodo and I have seen that sometimes the connecion is really slow (it can take 4-5 seconds after I open a link for a page to appear (for example if I type, sometimes it is fast, sometimes I have to wait 5 seconds before the page appears ).
On the web site Test your IPv6.
I see that the problem is with every IPV6 test that can take more than 4 seconds. As soon as I disable the IPV6 filtering, there is no problem at all.
Is there something I can do to speed the IPV6?
Am I missing something?
My computer is in Windows 10 Pro (all updates applied)

Thank you

You need to make specific ICMPv6 Allow In global rules, though I’m not sure which ICMP types/codes that you need to allow. You can try with creating an allow in rule for ICMPv6 Any and have that above any block rules.

Thank you for the explanation