How to save data in Json format in React-admin v3? - json

Question

I created JsonInput, which sends a json object to the input SimpleForm, however, a modified version of it gets into the Data Provider.
that's what is sent to the input:
json: {
"FunctionalGroup": [
{
"uaIDref": [
"2104"
],
"_Name": "Текущие параметры",
"_ID": "33"
},
{
"uaIDref": [
"2100"
],
"_Name": "Текущие параметры пониженной точности",
"_ID": "34"
},
],
"_Name": "Прибор 1",
"_ID": "32"
}
that's what came to the server:
json: {
"FunctionalGroup": [
{
"uaIDref": [
"2104"
],
"_Name": "Текущие параметры",
"_ID": "33"
},
{
"uaIDref": [
"2100"
],
"_Name": "Текущие параметры пониженной точности",
"_ID": "34"
}
],
"FunctionalGroupIds": "",
"_Name": "Прибор 1",
"_ID": "32"
},
after a response from the server with this object, this is what came in the field:
json: {
FunctionalGroup: [
{
uaIDref: [
'2104'
]
},
{
uaIDref: [
'2100'
]
}
],
FunctionalGroupIds: ''
}
what kind of magic is this?
I did some tests. When I converted the object to a string, the correct json was sent to the server, however, in the field after the server responded, the modified object was displayed again.
I found out that the conversion is related to redux.js, but what exactly happens is not understood.
Please give any comments on this.
How can I make save json?