Check your DHCP Server and disable DHCPv6. The raspi shouldn't get a ipv6 then and you won't have this problem in the future with other devices.
edit: and restart the pi after disabling DHCPv6
Check your DHCP Server and disable DHCPv6. The raspi shouldn't get a ipv6 then and you won't have this problem in the future with other devices.
edit: and restart the pi after disabling DHCPv6