MySQL made the following change with the introduction of MySQL 8.0.23 ( Changes in MySQL Connector/J 8.0.23):
Also, with the implementation of the new mechanism, a getObject(columnIndex) call on a DATETIME column returns a LocalDateTime object now instead of a String. To receive a String like before, use getObject(columnIndex, String.class) instead.
Confluence seems to work correctly, however, the following message flood the application logs:
Confluence should check for this change in MySQL and use getObject(columnIndex, String.class) as it appears this will be the process going forward for MySQL.
As of now, the only workaround is to downgrade to MySQL 8.0.22 driver.