Was the ability to add Communication (Notes) to NetSuite invoices via REST API removed?

In the past, I built logic to POST to the Notes endpoint for an Invoice in the NetSuite REST API in order to add Communication > User Notes:

It was a simple POST call to the /record/v1/note/ endpoint with a payload like this:

{
    "note": "Test note",
    "title": "Test",
    "transaction": { "id": "2213063" }
}

This code has been in place and working for quite a while but all of sudden I am getting an error when I call it:

{
    "type": "https://www.rfc-editor.org/rfc/rfc9110.html#section-15.5.5",
    "title": "Not Found",
    "status": 404,
    "o:errorDetails": [
        {
            "detail": "Record type 'note' does not exist.",
            "o:errorUrl": "/services/rest/record/v1/note",
            "o:errorCode": "NONEXISTENT_ID"
        }
    ]
}

Did something change that I missed?

EDIT: I found a recommendation online to use "entity" in place of "transaction" like this:

{
    "note": "Test note",
    "title": "Test",
    "entity": { "type": "invoice", "id": "2213063" }
}

This returns the same error.

After some back and forth with NetSuite support, the answer is they simply removed that endpoint. They claim it was a beta endpoint and they decided to remove it. So, as of today you can't add notes via integration.

Seems like an interesting choice to me and takes away an ability to allow our business to process invoices as we have but we will just have to adapt.