drop role command not working in my postgresql 11. I can't delete the role named 'ckdev' .

 Role name |                         Attributes                         | Member of 
-----------+------------------------------------------------------------+-----------
 ckdev |                                                            | {}
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

postgres-# drop role ckdev
postgres-# \du
                                   List of roles
 Role name |                         Attributes                         | Member of 
-----------+------------------------------------------------------------+-----------
 ckdev |                                                            | {}
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}