DML Monitoring not working for table.

For couple of tables in one of 11.1.0.7 database, DML monitoring is not working.as expected. The stats got last gathered for the table on 4th Mar and that shows no records for the table. However, the table is having 355446 records for now.. The table stats is not locked as shown below below and neither it appears to be STALE in dba_tab_statistics. I am not sure what is causing this or even if I am doing something wrong. Can we have someone to provide some insights on this please?

NAME                                               VALUE
       DESCRIPTION


--------------------------------------------------

------------------------------


--------------------------------------------------


_dml_monitoring_enabled                            TRUE
      enable modification monitoring

dba_tab_statistics:
OWNER                          TABLE_NAME
PARTITION_NAME                 STATT STA LAST_ANALYZED

• ----- --- ---------------------------

  ---

  DR_STORE28 CONTENT_MIG_WORKFLOW NO 04-MAR-2019 23:13:51 0

OWNER                          TABLE_NAME                     LAST_ANALYZED
                NUM_ROWS MON


------------------------------ ------------------------------


--------------------------- ---------- ---


DR_STORE28                     CONTENT_MIG_WORKFLOW           04-MAR-2019
23:13:51                 0 YES

SQL> select count(1) from DR_STORE28.CONTENT_MIG_WORKFLOW;

  COUNT(1)

    355446

i did flush of monitoring info to see if there was something there in memory that has not reflected in DBA_TAB_MODIFICATIONS, but that as well didn't help.

SQL> select object_id from dba_objects where object_name='CONTENT_MIG_WORKFLOW' and owner='DR_STORE28';

 OBJECT_ID

    302901

SQL> select * from sys.mon_mods$ where obj#=302901;

no rows selected

SQL> select * from sys.mon_mods_all$ where obj#=302901;

no rows selected

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