Post-migration, Atlas hook for HBase is not enabled by default on AM2CM migrated clusters. you must manually enable Atlas hook.

To enable the Hive Metastore hook in your Cloudera Manager instance:
  1. Log in to Cloudera Manager
  2. Select the HBase service
  3. Select Configurations tab
  4. Search for Enable Atlas Hook that the HBase service depends on and check this.
  5. Select Save Changes