Brought to you by the creators of Snap. Yeah that's probably the real issue. Don't touch anything by Canonical.
This is now part of the cloud images for Debian.
And then OVH makes you hand-configure your IPv6 address, with netmask and IPv6 gateway - no DHCP6 for their VPS servers. Then they put the footgun in your hand by not mentioning the double-quotes requirements which YAML has for IPv6-with-netmask.