Bug report

Some tables in oracle database have no primary key, but have a unique index.  When Xstream is used to capture changed data, ORA-26876 exception will be reported after running for a period of time.
The ALL_XSTREAM_OUTBOUND_PROGRESS information in the query database shows that the PROCESSED_LOW_POSITION field value of OUTBOUND SERVER is different from the lcr_position recorded by debezium in the file.  After converting lcr_position to the corresponding scn, it is found that the scn is smaller than the PROCESSED_LOW_SCN obtained from ALL_XSTREAM_OUTBOUND_PROGRESS.  After I replaced the lcr_position value recorded in the file with the queried PROCESSED_LOW_POSITION field value and restarted the debezium connector, the task returned to normal, but the problem continued to be reported after running for some time.  I wonder what might be the cause of this, or does the xstream approach not support capturing change data without a primary key table?