If you are, do not manually customize contents under the /etc/hive/conf path as this is a symlink to a command generated directory that can be redeployed at any point (from UI or API actions on the cluster).
Try storing your keytab at a different path.
P.s. If you are using CM, it should be managing your keytabs for you, so you can avoid such steps. Is this configuration used to customize the entries of the keytab in a way that CM cannot?