Symptoms
Assume that Change Data Capture (CDC) is enabled in Microsoft SQL Server 2016, 2017 or 2019. Because of a timing issue, CDC capture process may try to insert duplicate start_lsn in the table cdc.lsn_time_mapping, and you may receive an error message that resembles the following:
Violation of PRIMARY KEY constraint 'lsn_time_mapping_clustered_idx'. Cannot insert duplicate key in object 'cdc.lsn_time_mapping'. The duplicate key value is (Value).
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 updates for SQL Server:
Note: For this fix to take effect, you need to enable the Trace Flag (TF) 8291.
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.