Has anyone managed to successfully save the IPV6 settings? Specifically with BT?? 

I followed the TP Link Guide here: https://www.tp-link.com/uk/support/faq/2942/ but the router behaves weird when trying to save the settings. 

If i follow the instructions, it wont let me save, I get a error on the interface saving Operation Failed. If I follow the instructions, and press connect, it often says Operation Successful on the web interface, but the interface will glitch - i.e. the Share the same PPPoE session with IPv4 is no longer enabled or the box for the username and password is displayed as well as the tick box. 

I have managed to make it work and had IPV6 fully working, but then the router rebooted due to a powercut and stuck again with the interface errors. 

To confirm, the connection is BT, it is setup for IPV6. and all of the errors i am getting are via the web interface. have tried a few different browsers and confirmed that there are no plugins causing it. The rest of the interface is fine. Also did a factory reset and re-uploaded the latest firmware incase they were causing a problem, but still not having any of it. 

Error I see when trying to save the IPV6 settings at the bottom of the interface: 

Not sure if this a bug or something... very annoying though as the router is much better than the previous, just don't see that for a next gen gaming router this is so complicated. Have seen many having similar issues with not connecting and issues with the BT setup in patictular, but as TP Link offer a help file for the ISP assume this is a bug?