Field name overrides not being respected on PATCH requests

We've noticed that field name overrides are not being respected when issuing PATCH requests against the API when updating content. For example:

If our data is NOT using field name overrides, we would update it with a PATCH request looking something like this:

{
  "data": {
    "type": "my_type",
    "id": "84accc31-09f9-4c4e-bca2-511f5f0b0171",
    "attributes": {
      "name": "My Content",
      "field_data_1": "Some updated text Content",
    }
  }
}

This updates correctly.

However, if we modify the field name - in this instance just removing the Drupalism of 'field_data_1' and calling the field 'data_1'....

{
  "data": {
    "type": "my_type",
    "id": "84accc31-09f9-4c4e-bca2-511f5f0b0171",
    "attributes": {
      "name": "My Content",
      "data_1": "Some updated text Content",
    }
  }
}

Sending this patch request returns an error:

"The provided field (data_1) does not exist in the entity with ID 84accc31-09f9-4c4e-bca2-511f5f0b0171."