IPV6 only works after restart firewall

Hello,

Lately there some change in my network and I cannot get IPV6 to work again. After turn off firewall for some seconds and turn on again, IPV6 starts to work. Any hints?

Thanks!

Network config:

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

config globals 'globals'
option ula_prefix 'fd4e:1d2a:5a3d::/48'

config interface 'lan'
option type 'bridge'
option ifname 'eth0.1'
option proto 'static'
option ipaddr '192.168.120.1'
option netmask '255.255.255.0'
option ip6assign '60'

config interface 'wan'
option ifname 'eth1.2'
option _orig_ifname 'eth1.2'
option _orig_bridge 'false'
option proto 'pppoe'
option username'---------'
option password '---------'
option ipv6 'auto'
option metric '10'

config interface 'wan6'
option _orig_ifname 'eth1.2'
option _orig_bridge 'false'
option proto '6to4'

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

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

config switch_vlan
option device 'switch0'
option vlan '2'
option ports '4 6t'
option vid '2'

config switch_vlan
option device 'switch0'
option vlan '3'
option vid '3'
option ports '0 6t'

config interface 'wan_'
option ifname 'eth1.3'
option _orig_ifname 'eth1.3'
option _orig_bridge 'false'
option proto 'dhcp'
option metric '20'

Firewall

config defaults
option syn_flood '1'
option input 'ACCEPT'
option output 'ACCEPT'
option forward 'REJECT'

config zone
option name 'lan'
option input 'ACCEPT'
option output 'ACCEPT'
option forward 'ACCEPT'
option network 'lan'
option conntrack '1'

config zone
option name 'wan'
option input 'REJECT'
option output 'ACCEPT'
option forward 'REJECT'
option masq '1'
option mtu_fix '1'
option network 'wan wan6 wan6_ wan_'
option conntrack '1'

config rule
option name 'Allow-DHCP-Renew'
option src 'wan'
option proto 'udp'
option dest_port '68'
option target 'ACCEPT'
option family 'ipv4'

config rule
option name 'Allow-Ping'
option src 'wan'
option proto 'icmp'
option icmp_type 'echo-request'
option family 'ipv4'
option target 'ACCEPT'

config rule
option name 'Allow-IGMP'
option src 'wan'
option proto 'igmp'
option family 'ipv4'
option target 'ACCEPT'

config rule
option name 'Allow-DHCPv6'
option src 'wan'
option proto 'udp'
option src_ip 'fc00::/6'
option dest_ip 'fc00::/6'
option dest_port '546'
option family 'ipv6'
option target 'ACCEPT'

config rule
option name 'Allow-MLD'
option src 'wan'
option proto 'icmp'
option src_ip 'fe80::/10'
list icmp_type '130/0'
list icmp_type '131/0'
list icmp_type '132/0'
list icmp_type '143/0'
option family 'ipv6'
option target 'ACCEPT'

config rule
option name 'Allow-ICMPv6-Input'
option src 'wan'
option proto 'icmp'
list icmp_type 'echo-request'
list icmp_type 'echo-reply'
list icmp_type 'destination-unreachable'
list icmp_type 'packet-too-big'
list icmp_type 'time-exceeded'
list icmp_type 'bad-header'
list icmp_type 'unknown-header-type'
list icmp_type 'router-solicitation'
list icmp_type 'neighbour-solicitation'
list icmp_type 'router-advertisement'
list icmp_type 'neighbour-advertisement'
option limit '1000/sec'
option family 'ipv6'
option target 'ACCEPT'

config rule
option name 'Allow-ICMPv6-Forward'
option src 'wan'
option dest '*'
option proto 'icmp'
list icmp_type 'echo-request'
list icmp_type 'echo-reply'
list icmp_type 'destination-unreachable'
list icmp_type 'packet-too-big'
list icmp_type 'time-exceeded'
list icmp_type 'bad-header'
list icmp_type 'unknown-header-type'
option limit '1000/sec'
option family 'ipv6'
option target 'ACCEPT'

config rule
option name 'Allow-IPSec-ESP'
option src 'wan'
option dest 'lan'
option proto 'esp'
option target 'ACCEPT'

config rule
option name 'Allow-ISAKMP'
option src 'wan'
option dest 'lan'
option dest_port '500'
option proto 'udp'
option target 'ACCEPT'

config include
option path '/etc/firewall.user'

config forwarding
option dest 'wan'
option src 'lan'

config include 'miniupnpd'
option type 'script'
option path '/usr/share/miniupnpd/firewall.include'
option family 'any'
option reload '1'

Configure the firewall to log rejected packets on the WAN interface, and see what is the firewall blocking; then allow it.

Found the problem.
MWAN3 was preventing ipv6.

Fix found here