Wrt1200 v1 ipv6

I've been having some odd issues with ipv6 recently, i get an ipv6 address with -

latest OpenWrt trunk

latest Kong DD-WRT

connected directly to modem

I don't get an ipv6 address with -

Linksys stock firmware

Latest LEDE trunk

Here's my current configs, LEDE Reboot SNAPSHOT r3198-74ea99b (/etc/config/network) -

config interface 'lan'
	option type 'bridge'
	option ifname 'eth0'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config interface 'wan'
	option ifname 'eth1'
	option proto 'dhcp'
	option peerdns '0'
	option dns '208.67.222.222 208.67.220.220'

config interface 'wan6'
	option ifname 'eth1'
	option proto 'dhcpv6'
	option reqaddress 'try'
	option peerdns '0'
	option dns '2620:0:ccc::2 2620:0:ccd::2'
	option reqprefix 'auto'

I've also tried force ipv6 and prefix 64 and 56 with no luck, just wondering if anyone might have an idea of what's going on, thanks.

edit - I saw that 17.01 RC was available so i flashed it, but still no ipv6, strange.