I did it with and without above.

Here it is again.

SQL> exec dbms_mview.refresh('TBL_SIC');
BEGIN dbms_mview.refresh('TBL_SIC'); END;

*
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00201: identifier 'DBMS_MVIEW.REFRESH' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored


Now when I created a new test synonym it invokes the underlying package and fails for a user error.

This tells me the synonym is messed up and should be re-created no ?

CREATE public SYNONYM test FOR sys.DBMS_SNAPSHOT;

SQL> exec test.refresh('TBL_SIC');
BEGIN test.refresh('TBL_SIC'); END;

*
ERROR at line 1:
ORA-23401: snapshot "SYS"."TBL_SIC" does not exist
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 617
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 674
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 654
ORA-06512: at line 1