REST Web Services - Create Child Instance

Hi,

Im trying to create an instance in postman but the child always gets ignored.

Main class: YPROSHIP (key: YIDPR)

Child class: YPRSHYPREQ ... (key: YIDPR + YIDEQ)

If I make a details request, I get this answer:

"

{
.....
"$uuid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
"YCLIENTE": "00001",
"YDATA": "2017-04-12",
"YDESC": "RECORD INSERTED VIA REST",
"YIDPR": "WEC13529",
"YNOME": "TESTE REST",
"YNOMECLIENTE": "TEMP CLIENT",
"YPRSHYPREQ": [
{
"$uuid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
"YCOMENTARIOS": "Delivered at Liscont S.A. terminal.",
"YPRSH_YPREQ_YDATA": "2017-04-10",
"YESTADO": 3,
"YPRSH_YPREQ_YIDEQ": "GESU151511",
"YPRSH_YPREQ_YIDPR": "WEC13529",
"YLOCAL": "PTLIS",
"YPRSH_YPREQ_YTIPO": 1,
"$properties": {
"YPRSH_YPREQ_YIDPR": {
"$isMandatory": true
},
"YPRSH_YPREQ_YIDEQ": {
"$isMandatory": true
}
}
}

],
"YTIPO": 1,
"YTRANS": 2
}"

If I try to create (I'm trying with POST mode with mandatory fields only):

"{

"YIDPR": "FATHER1",
"YPRSHYPREQ": [
{
"YPRSH_YPREQ_YIDEQ": "SON1",
"YPRSH_YPREQ_YIDPR": "FATHER1",
"YLOCAL": "PTLIS",
"YPRSH_YPREQ_YTIPO": 1
}
]
}"

I get the answer:

{
...
"$uuid": xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
"YIDPR": "FATHER1",
"$links": {
"$save": {
"$isAction": true,
"$method": "POST"
}
}
}

My father instance was created, but child instance was ignored....

What should I do?

Best Regards