LoRaWAN IoT Core Downlink / Send data to device / Value 'null' at 'WirelessDeviceType'

Hello,

when i am trying to send a Downlink to a lorawan device and want to check the message queue in the aws console IoTCore -> Wireless connectivity -> Devices -> specific device: i am receiving this error as a red notification error pop up after a few seconds.

Value not valid 1 validation error detected: Value 'null' at 'WirelessDeviceType' failed to satisfy constraint: Member must have non-null and nonempty value

Althought i get no error message if i invoked the send data to device API from the CLI command line or from an lambda function using boto3. Also when i am using the console to queue a downlink i got a green conformation box but afterwars this error and nothing is displayed in the downlink queue section.

All the devices send the data normally and apart from this issue everything seems to work just fine. I have no clue why i am getting this error and i found nothing in the documentation. Did anyone encountered the same problem and knows how to solve it ?

Thanks for your help in advance.