Can not change ipv6 mode on AirPort Extreme 802.11ac
My ISP is now supporting IPV6 and I am trying to configure my Airport Extreme 802.11ac to use it: it is currently set to Link-local only using the Airport utility on my iPhone (iOS 9.3.1). Unfortunately, if I select Automatically or Manually the tick immediately moves back to Link-local only.
I've tried this using both my iPhone, iPad and Mac with no success.
I've rebooted the AirPort Express, which makes no difference.
Any idea what is happening (or more accurately not happening)?
Airport Extreme 802.11ac-OTHER