My cellphone is Oneplus 7 Pro, Android 9, latest oneplus official OS. When I am using the 4G network, IPv6 works fine. If I am connected to my WIFI, I can't visit IPv6 site on my Android phone. However, laptop and iPhone works fine. I can see in the WIFI status, I already been assigned with proper IPv6 addresses. Anyone know if this is a known issue or having any idea how to fix that? Thanks in advance!