Custom key mappings get NPE error

[imperio-wxm]

circe-core veresion: 2.12_0.14.1

case class AIRequest(requestId: String, height: Int, width: Int, inputs: List[InputData])
case class InputData(base64Array: String, dataType: String, shape: List[Int], layout: String)

implicit val requestBar: Encoder[AIRequest] = 
    Encoder.forProduct4("id", "width", "height", "inputs")(b => (b.requestId, b.width, b.height, b.inputs))
implicit val dataEncoder: Encoder[InputData] = 
    Encoder.forProduct4("array", "dtype", "shape", "layout")(b => (b.base64Array, b.dataType, b.shape, b.layout))

describe("json test") {
  it("bean to json") {
    val inputData = InputData("aaa", "uint8", List(3, 256, 256), "test")
    val aIRequest = AIRequest("bbb", 256, 256, List(inputData))
    println(aIRequest.asJson.noSpaces)
  }
}

Error:

java.lang.NullPointerException was thrown.
java.lang.NullPointerException
	at io.circe.MidPriorityEncoders$IterableAsArrayEncoder.encodeArray(Encoder.scala:919)
	at io.circe.Encoder$AsArray.apply(Encoder.scala:744)
	at io.circe.Encoder$AsArray.apply$(Encoder.scala:744)
	at io.circe.MidPriorityEncoders$IterableAsArrayEncoder.apply(Encoder.scala:911)
	at io.circe.ProductEncoders$$anon$4.encodeObject(ProductEncoders.scala:50)
	at io.circe.Encoder$AsObject.apply(Encoder.scala:824)
	at io.circe.Encoder$AsObject.apply$(Encoder.scala:824)
	at io.circe.ProductEncoders$$anon$4.apply(ProductEncoders.scala:47)
	at io.circe.syntax.package$EncoderOps$.asJson$extension(package.scala:8)