bleh i thought my #ipv6 prefix would be very stable, but apparently it isn't.
i haven't confirmed yet, but it probably changes every time the router reboots. that shouldn't happen too often, but it does happen occasionally and thus is not reliable enough for a server.
i was planning to use #octodns anyway, so i think https://github.com/octodns/octodns-ddns will do the trick. with a low TTL of 1 minute it should be reliable enough 🤞
just a bit annoying, that then the dns settings are applied by the server and not my desktop as part of the overall configuration (but there is no other way if the ip can change randomly).