Reference type does not work correctly

1. Define a reference property
2. Define the reference as
"com123":

{ "$type": "ref", "$id": "xxxxx(object id)", "$objectType": "objects.RefCom" }

3. Save
4. Can see the saved results
5. Refresh, saved contents lost

In the documentation, we can see a embedded object type, but from my understandings, it should be the ref type, please correct me if i'm wrong
"
Embedded Objects

When the property holds an embedded object, you can “reach into” the embedded object using dot notation.

In the following example, the query uses the dot notation to match all objects where, value of the producer property is an embedded object with its company property set to 'ABC123':

{
"producer.company": "ABC123"
}
"