OVH IPv6 Reverse DNS not working despite IPv6 pinging

I setup MIAB on a new OVH server (I’m going to use outbound relay to get around OVH’s bad IP reputation.)

Brand new Ubuntu 22.04 install. IPv4 and IPv6 configured and pinging. I successfully was able to setup Reverse DNS for the IPv4 no problem.

However, if I try to configure box.mydomain.com for IPv6 Reverse DNS in OVH’s panel, I get the following error:

An error has occurred updating the reverse path. Cannot check if box.mydomain.com. resolves to 2604:2dc0:0101:0200:0000:0000:0000:xxxx

Which is simply not true. If I perform a ping6 box.mydomain.com I see the ping results coming back with my VPS’ IPv6 address.

OVH seems to be a little wonky, but their Epyc servers are cheap and fast! I’d really like to get this working.