This is an issue with data that is updated in DWH_FIN_TRANSACTION_FACTS but not in DWH_FIN_TRANSACTION. So the foreign keys cannot connect to the parent key as they are missing.
Manually remove the values with query:
delete from DWH_FIN_TRANSACTION_FACTS where TRANSACTION_KEY not in
(select TRANSACTION_KEY from DWH_FIN_TRANSACTION)
Ensure nothing else is running on the application-level that updates the records last_updated_date as per Article ID 103730.