Symptoms
When you install SQL Server 2019 or when you upgrade from prior versions, you are unable to execute sys.dm_exec_requests as it gets blocked on metadata permissions lookup that's blocked by Remote Harden (HADR_SYNC).
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative update for SQL Server:
About cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
References
Learn about the terminology that Microsoft uses to describe software updates.
