We just set up PRTG to evaluate it. Added a SQL Server and after enabling WMI firewall rules, the auto-discovery worked fine and added a few sensors.
However, when we try to manually add the WMI Microsoft SQL Server 2016 sensor, we get the error:
8004100E: The namespace specified could not be found
Version is PRTG Network Monitor 220.127.116.118 x64 running on Windows Server 2019 Datacenter