Oracle XMLTable fails when the xml to parse is too long

I'm working with soap web services and trying to parse an xml with the oracle XMLtable command and inserting it into a table fails when the xml has many lines (2 million). It works well when the file has few lines. This is a summary of the command.

BEGIN
INSERT INTO TT_P_
SELECT *
  FROM TT_P_WS_RESPONSE a, XMLTable( //Unit' PASSING XMLTYPE(a.xml)
    COLUMNS id...NUMBER(19) PATH...,
  ) t;

Does anyone have any idea of what may be happening?

Greetings and thank you very much