Error changing owner in Azure Postgres with superadmin

Question

I hope anyone can tell me what I am doing wrong here. I have upgraded an Azure Postgres PaaS database from version 10 to 11. I've just followed the Microsoft guide for doing the upgrade. All went fine and after recreating the private endpoints, I found myself unable to change the owner of all tables which are not in the public schema.

Apparently using the Microsoft procedure with pg_dump and pg_restore is not keeping the original ownership, so when I executed the pg_restore all the tables are now owned by the default user.

Here is my scenario

Source Database ( v 10 )

psql --host=$PGBACKUP --port=5432 --username=$PGBACKUPUSER dbname=postgres
psql (11.2, server 10.17)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

postgres=> \du
                                                         List of roles
             Role name             |                         Attributes                         |          Member of
-----------------------------------+------------------------------------------------------------+------------------------------
 GRP_AZURE_SCTS_HCBE_SQL_ADMIN_PRO | Create role, Create DB                                     | {azure_ad_admin}
 azure_ad_admin                    | Cannot login                                               | {azure_pg_admin}
 azure_ad_mfa                      | Cannot login                                               | {}
 azure_ad_user                     | Cannot login                                               | {}
 azure_pg_admin                    | Cannot login                                               | {}
 azure_superuser                   | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
 posadmn001                        | Create role, Create DB                                     | {azure_pg_admin,wsalesadmin}
 schma_usr                         |                                                            | {}
 wsalesadmin                       |                                                            | {}

postgres=> \dt swp_4eyes_hcbe_cert.approve_locks 
                     List of relations
       Schema        |     Name      | Type  |   Owner
---------------------+---------------+-------+------------
 swp_4eyes_hcbe_cert | approve_locks | table | wsalesadmin

Target Database ( v 11 )

$ psql --host=$PGSOURCE --port=5432 --username=$PGSOURCEUSER dbname=postgres
psql (11.2, server 11.12)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

postgres=> \du
                                                         List of roles
             Role name             |                         Attributes                         |          Member of

-----------------------------------+------------------------------------------------------------+---------------------
---------
 GRP_AZURE_SCTS_HCBE_SQL_ADMIN_PRO | Create role, Create DB                                     | {azure_ad_admin}
 azure_ad_admin                    | Cannot login                                               | {azure_pg_admin}
 azure_ad_mfa                      | Cannot login                                               | {}
 azure_ad_user                     | Cannot login                                               | {}
 azure_pg_admin                    | Cannot login, Replication                                  | {}
 azure_superuser                   | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
 posadmn001                        | Create role, Create DB, Replication                        | {azure_pg_admin,wsal
esadmin}
 schma_usr                         |                                                            | {}
 wsalesadmin                       |                                                            | {}



  postgres=> \dt swp_4eyes_hcbe_cert.approve_locks
                    List of relations
       Schema        |     Name      | Type  |   Owner
---------------------+---------------+-------+------------
 swp_4eyes_hcbe_cert | approve_locks | table | posadmn001
(1 row)

Either using REASSING or ALTER TABLE xxx OWNER TO gives me this error ( see below ). I really don't get it, so if I am the superadmin why I can't do this ?

postgres=> alter table swp_4eyes_hcbe_cert.approve_locks owner to wsalesadmin;
ERROR:  permission denied for schema swp_4eyes_hcbe_cert
postgres=>

OR

postgres=> REASSIGN OWNED BY posadmn001 TO "wsalesadmin" ;
ERROR:  permission denied for schema swp_stocklist_hcbe_cert

What I am doing wrong ? Why I can't change the ownership of these tables in this schema to same owner as it was the source database ?

Thank you