Symptoms
In Microsoft SQL Server 2019 on Linux, when you run a sp_execute_external_script query that has passthrough data OutputDataSet = InputDataSet that includes a nvarchar data type column, the data size or length of Unicode string in the nvarchar column that is returned in the output data set is larger than that in the input data set.
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.