Ipv6 not working on android but works on iphone

ipv6 works on iphone and ubuntu desktop but not android
i can see ipv6 is alloted to my device on android but ipv6 hosts are not accessible

on android I get error
unknown host: ipv6.google.com
while ipv4.google.com resolves fine

i disabled DHCPv6 on Openwrt LAN and enabled only SLAAC
still it wont work

i googled over 20 times and tried everything.. nothing worked

ISP assigns /64 subnet for public IPV6 and for local ipv6 i have set subnet as /56

what to do?

cat /etc/config/network

config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'

config globals 'globals'
option ula_prefix 'fdc1:5997:47ce::/48'

config device
option name 'br-lan'
option type 'bridge'
list ports 'eth0.1'

config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option ip6assign '56'

config device
option name 'eth0.2'
option macaddr '14:eb:b6:8a:cf:0a'

config interface 'wan'
option device 'eth0.2'
option proto 'pppoe'
option username 'zzz'
option password 'zzzzz'
option ipv6 'auto'
option peerdns '0'
list dns '1.1.1.1'
list dns '208.67.220.220'
list dns '2606:4700:4700::1001'
list dns '2620:119:53::53'

config interface 'wan6'
option device 'eth0.2'
option proto 'dhcpv6'
option reqaddress 'try'
option reqprefix 'auto'
option peerdns '0'
list dns '2606:4700:4700::1001'
list dns '2620:119:53::53'

config switch
option name 'switch0'
option reset '1'
option enable_vlan '1'

config switch_vlan
option device 'switch0'
option vlan '1'
option ports '2 3 4 5 0t'

config switch_vlan
option device 'switch0'
option vlan '2'
option ports '1 0t'

https://issuetracker.google.com/issues/36949085#comment266

Google refuses to support DHCPv6 as per the standards. They ONLY allow SLAAC.

its marked as wont fix.

https://lostintransit.se/2020/05/22/its-2020-and-androids-ipv6-is-still-broken/

i have disabled IPV6 and enabled SLAAC but ipv6 is not connecting.
it might be problem specific to me and that's why i need help.

Is it even a question that Apple has better new age tech developement support than Android?

Android doesn’t have WPA3 either, at least not my Samsung. iOS has had wpa3 support for many years now, iOS 13 if I remember right.

that does not answer my question at all
i am not here for a android vs apple discussion.
i know DHCPV6 is not supported on android. but SLAAC is supported.
i have getting it working

Duplicate: Ipv6 only on openwrt router not on LAN