Retrieve 1:n relationship records from ODATA4

Hi Team,

We want to retrieve a specific record by Id along with all the related elements (eg - Retrieve Account A with all of its related Contacts). 

What we already know:

We can retrieve the account record itself along with related records that are linked with lookupfields, like the PrimaryContact

Account(0001111-1111-1111-1111-111111231123)?$expand=PrimaryContact($select=Name)

This works, but it returns only one contact, the primary one.

Instead, we need an embedded list of contacts, like

{
    "@odata.context": myurl.creatio.com/0/odata/$metadata#Account(PrimaryContact(Name))/$entity,
    "Id": "22222-222222-2222-222222-22222207ba6",
    "Name": "somename",
    "OwnerId": "111111-11111-11111-11111-1111111",
    "CreatedOn": "2022-11-16T21:11:57.214167Z",
    "Contacts“ : [
{object}, {object}
]
}

Given the first URL in the response, we expected that all NavigationProperties would behave the same:

But this collection:

Is not accessible. If we call for :

Account(0002204c-d255-46c0-bea6-0f32e2e07ba6)?$expand=ContactCollectionByAccount

We get this error in return:

{
    "error": {
        "code": "",
        "message": "An error has occurred."
    }
}

If we use other expand values, we retrieve meaningful errors like „Could not find a property named xy“, but this error is not self explaining. How can we return an object with an embedded list of children? I know that in this example we also could ask for a list of Contacts filtered by their account, but we cannot do that in all scenarios we have in mind.

Thank you

Petrika