Acumatica API not updating multiple Contacts under Customer records

We are trying to create an integration with Acumatica API and we are encountering issues or weird behavior when updating multiple items in a parent record.

For example when we try to update multiple contacts for a customer, it won't update the all contacts but only update the first one, but the weird thing is it picks up the values from the second item to update the first item, like the contact note field of second item will replace the contact note field of the first item, we are not sure if its bug or something.

Anyone experience the same issues?

Here is my sample Json payload for a Customer PutEntity endpoint, the note for ContactID: 100745 will replace the note for ContactID: 100743, but will not touch the second item.

Seems like only first Contact gets updated.

{
  "id": "01a0c017-df7f-ea11-8175-b9d61cb73193",
    "Contacts": [
    {
      "note": {
        "value": "Note for 100743"
      },
      "ContactID": {
        "value": 100743
      },
    },
    {
      "note": {
        "value": "Note for 100745"
      },
      "ContactID": {
        "value": 100745
      }
    }
  ],

}