Missing output attribute in AWS Step function

I have two Express type step function (named it as A and B) that running the same template code as below and with the same input but different lambda. However, Step Function B execution response under details, has missing output attribute.

Wondering what's causing the missing output attribute? I've checked in cloudwatch log of both lambda, and they both actually returning the correct response with value.

{
"StartAt": "OrderInvoker",
"States": {
"OrderInvoker": {
"End": true,
"Type": "Task",
"InputPath": "$",
"Resource": "arn:aws:states:::lambda:invoke",
"Parameters": {
"FunctionName": "arn:aws:lambda:us-east-1:XXXXXX:function:order-invoker:$LATEST",
"Payload": {
"order.$": "$.order"
}
}
}
}
}
With output attribute
https://i.stack.imgur.com/8wHX6.png
Missing output attribute
https://i.stack.imgur.com/bykwS.png