I have a VPS server from OVH running Ubuntu 18.04 LTS and I noticed today that the IPv6 was not working at all, nor was the IPv6 assigned to me listed when I looked in ifconfig. Then I followed the OVH guide here and I followed the section for my version of Ubuntu and edited my netplan accordingly. However, although I can see my IPv6 address when I type ifconfig, it does not establish a connection when I attempt to ping an ipv6 address or make any other connections with IPv6. I have followed the guide exactly and made sure I had followed it properly so I am not sure why it's not working and would appreciate any help on what I'm missing with this. I have pasted my 51-cloud-init-ipv6.yaml below (2001:db8:555:555::2a11 represents my assigned IPv6 address in the OVH control panel and 2001:db8:555:555::1 represents the gateway)
network:
version: 2
ethernets:
ens3:
dhcp6: false
match:
name: ens3
set-name: ens3
addresses:
- "2001:db8:555:555::2a11/128"
gateway6: "2001:db8:555:555::1"