Status column items_by_column_values query Fails on query by status_index

status column items_by_column_values query
only works when value is a label and not an index

value = status_label = "done"  # query works
value = status_index = 1 # query fails

This query WORKS.

query {
  items_by_column_values (board_id: 12345678, column_id: "status",
  column_value: "done") {
    id
    name
    column_values {
      id
      title
      value
    }
  }
}

These queries FAIL: (identical query, except the below column value)

column_value: 1
column_value: "1"
column_value: {"index": 1}
column_value: {"index": "1"}
column_value: '"{\\"index\\": 1}"'
column_value: '"{\\"index\\": \\"1\\"}"'

Is this a feature or a bug?