3624567 - DBSQL_DUPLICATE_KEY_ERROR During INSERT Despite No Existing Duplicate Entry

The following error occurs during execution of change document-related transactions or processes in an SAP S/4HANA system:

Category               ABAP Programming Error  
Runtime Errors         DBSQL_DUPLICATE_KEY_ERROR  
Exception              CX_SY_OPEN_SQL_DB  
ABAP Program           SAPLSCD0  

Additionally, trace logs (e.g., HANA indexserver traces) may show failed attempts to insert into e.g. table CDPOS with errors like:

Failed to execute trigger 'SAPABAP1:CDPOS_I_<TRIGGER_NAME>_TRIG (triggered by INSERT on table SAPABAP1:CDPOS)'

Despite the dump message referencing a duplicate key error, manual verification via SE16 or SQL shows no existing entry with the conflicting key in the target table (CDPOS).

KBA , HAN-DB , SAP HANA Database , Problem