SQL output differs between 11G and 12c

SQL output differs between 11G and 12c. In 11G the update statement updates the records with values whereas in 12c version the update of the filed value is with NULL.

UPDATE table_name1 bwd

      SET (bwd.column1) =

          (SELECT bdc.column1

             FROM table_name2         bwi,

                  table_name3      bwo,

                  table_name4 bdc

            WHERE bwi.column2 = bwd.column2

              AND bwi.column3 = bwo.column3

              AND (bwi.column4 = bdc.column2 OR bwi.column5 = bdc.column3)

              AND bwo.column5 = bdc.column5

              AND substr(bwi.column6, 1, 8) =

                  substr(bdc.column6, 1, 8)

           ),

          column7 = 1,

          column8 = 1,

          column9 = 1,

          column10 = -1

    WHERE bwd.column3 = 202011263543642;

Please help me to understand the difference.