Enable use of rpcbind. This is required for Gluster's NFS functionality.
You may want to turn it off to reduce the attack surface for DDoS reflection attacks.
See https://davelozier.com/glusterfs-and-rpcbind-portmap-ddos-reflection-attacks/ and https://bugzilla.redhat.com/show_bug.cgi?id=1426842 for details.