Hi,

I've switched provider today and I'm now using PPPoE on VLAN 6 (default KPN fiber settings in The Netherlands). 

IPv4 went smooth and works awesome.

IPv6 gives an instant error as soon as I enable it. I tried rebooting, different methods, etc. I once got it to work with below settings, but after a reboot I never managed to set it up again.

The error as soon as I enable the toggle (before even being able to make settings), all settings I try to make hereafter are not being saved (probably as the error already indicates):

These are the settings that I'm trying to make and worked for a couple hours:

After pressing Save, it returns and toggles the ipv6 switch automatically to Off.