Symptoms
A SELECT query that uses a batch mode hash aggregate operator that counts multiple nullable columns in the query execution plan returns incorrect results in SQL Server. This may occur when you use column store indexes, although it depends on the query pattern. For example, you may notice it for queries that use a PIVOT clause.
Resolution
This fix is included in the following cumulative updates for SQL Server:
Cumulative Update 4 for SQL Server 2017
About SQL Server builds
Each new build for SQL Server contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the following latest builds for SQL Server:
Latest cumulative update for SQL Server 2017
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology Microsoft uses to describe software updates.