pg_event_trigger_ddl_commands after GRANT is quite empty

Dear Postgres Community,

pg_event_trigger_ddl_commands after GRANT is quite empty.

If I execute: GRANT SELECT ON TABLE t TO r;

. and in a trigger function I have:

SELECT classid, objid, objsubid, command_tag, object_type, schema_name, object_identity
FROM pg_event_trigger_ddl_commands();

This gives me:

null, null, null, GRANT, TABLE, null, null

How to find out the table involved and the privileges?

Regards,
Franz-Josef Färber