Super Account lacking permissions in Postgresql 16+

[Ragge-dev]

Background

Hello 👋
I'm trying to create a superuser using the volcengine_rds_postgresql_account resource like this:

resource "volcengine_rds_postgresql_account" "db_owner" {
  account_name     = "db_owner"
  account_password = "my-secret-password"
  account_type     = "Super"
  instance_id      = "my-db-instance-id"
}

I then want to create new roles in the database and add those roles to the db_owner role. I created one postgresql 15 and one 17 instance with one database each and added the db_owner role as above, however granting new role memberships to the db_owner role doesn't work on postgresql 17, even though I am running these operations as db_owner which is a "Super Account".

I am using the command grant db_owner to test_role with admin option granted by current_role as it gives a better error message, running grant db_owner to test_role with admin option also fails.

Postgresql 15

Postgresql 17

Expected behaviour

My expected behaviour is that I would be able to add new roles to the db_owner role (as db_owner) when running postgresql 17. I haven't been able to work around this so far, it's currently holding us back from upgrading our postgresql instances up from version 15. Any help would be appreciated!