Kerberos + NFSv4 : file ownership nobody:nobody after mount?

Does anyone know why files are showing nobody:nobody ownership using Kerberos and secure NFSV4 with MacOS? kinit user mount -t nfs -o vers=4,sec=krb5 IP:/export/nfs-test /Volumes/export/mnt I note that, if I create a file on the mount, on MacOS it is owned by nobody, but when I check on the NFSv4 server, it has the correct ownership user. I'm not sure if this is some relationship between idmapd, MacOS NFSv4 implementation or perhaps some infrastructure misconfiguration. I have a DNS server, however LDAP isn't configured. Perhaps there need to be some GID/UID mapping on MacOS available via LDAP?