Finding PO line related to a GLTRANS record

GLTRANS.OBJ_ID value of 1619218 shows transaction amount of $3,658.81. GLTRANS.R_SYSTEM is 'PO' so we should be able to find the details of this GLTRANS record in MMDIST. Linking to MMDIST with query

SELECT *
FROM GLTRANS inner join mmdist on gltrans.obj_id = mmdist.rni_obj_id
WHERE gltrans.obj_id=1619218

shows 4 records totalling $3,109.81. 1 MMDIST record is omitted. We can find it in MMDIST because we were told by the client is it PO 69546. For that record, the value of MMDIST.RNI_OBJ_ID = 1744634 and MMDIST.GLT.OBJ.ID = 0. So we can't find a way to link to that from GLTRANS.

Question is how to find the details of this record when all we know about it is that it's associated with GLTRANS.OBJ_ID=1619218. We cannot select from MMDIST by POSTED_DATE because this record shows a POSTED_DATE out of the range of the month of the GLTRANS record it is associated with.