Today, 18th January 2022, The Database patch bundles were released.
All the details on MOS in Doc ID 19202201.9 and Doc ID 21202201.9 are recommended to be installed on production systems.
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In 19c or higher, it is no longer necessary to enable ‘Shared Servers’ on the catalog database, so Oracle recommends that (if you are using Oracle Native Encryption with sharding) you disable Shared Servers on the catalog database. This can be done by setting the database parameter shared_servers to “0” and restarting Oracle. Note that this is a global parameter set in the Container Database.