Ec200t-cn ipv6 not working on openwrt

Hello,i am configuring ec200t-cn modem on openwrt with luci-proto-modemmanager.

I selected ipv4 /ipv6 as my ip class,
But i can only see ipv4 address on my modem after internet connection dialed up successfully.
Depending on the official document (the link is below) from you,Ipv6 is supported by ec200t-cn since firmware version EC200TCNDAR02A13M16.
Meanwhile my firmware version Is already EC200TCNDAR02A15M16.

You can try again after upgrading the version, the version will be emailed to you.