The geometry field inserts data into 12C and uses get_ Wkt() function query, the result is wrong

Hello, I would like to ask you or the Oracle Technical support team a question:

In oracle12c database, SQL: "insert into tablename" is used

(ID, GEOMETRY)

VALUES

(1,

SDO_ GEOMETRY(2003,

4326,

NULL,

SDO_ ELEM_ INFO_ ARRAY(1, 2003, 1),

SDO_ ORDINATE_ ARRAY(115.48883, 36.59252, 115.4887, 36.59164,115.48883, 36.59252 )));"

Insert spatial geometry data into the spatial table, and then use get_ Wkt() function query, the beginning of the result should be "polygon ((115.48883, 36.59252, 115.4887, 36.59164, 115.48883, 36.59252))", but now the result is ", (115.48883, 36.59252, 115.4887, 36.59164, 115.48883, 36.59252))", the query result is different from the expected, but this problem is not found in 11g version. How did this bug come into being? How to avoid this problem?