It turns out at one point it got misconfigured as we lost the redirection from
https://wikimedia.es/.well-known/webfinger, so while existing accounts were still reachable, this one being a new one was not. I see that other instances that were not finding it now are able to locate it, but wikis.world is still failing. The DNS should have propagated already, but it may have cached the negative result.
I have also retooted the latest message, which may have other instances find out the new account.