When ApexSQL Audit is upgraded to version 2019 R1 and audited SQL Server instance is SQL Server 2012 or higher, events will not be audited per previously set configuration
The origin of this issue is a defect in the 2019 R1 version which is manifested when Extended Events are set as an auditing mechanism for applicable SQL Server versions (2012 or higher). During the update, the auditing mechanism is changed from ‘trace’ to ‘auto’ which is actually Extended Events’ for SQL Servers 2012 onwards.
WORKAROUND
A quick workaround for this issue is to change auditing mechanism back to SQL traces.
To do this, perform the following steps:

With this, auditing will continue to work in the same manner as before the update.
RESOLUTION
To completely resolve this issue, perform an upgrade to the ApexSQL Audit 2019 R2 (or higher) version which includes a fix of the described bug in the 2019 R1 software version.
To update to the latest version, click on the Get updates button in the Resources tab of the main menu and complete the update process if an update is available:
