Placeholder not showing up in input.choice

[vivekhumnabad]

sampleJSON.txt
Please refer to the attached text file for JSON response I am trying out.
"type": "Input.ChoiceSet",
"id": "ptoInput",
             "placeholder": "Select Type ...",
             "style": "compact",

Placeholder is not working if I use in Input.ChoiceSet. Same works in web when i try the same JSON here -
https://adaptivecards.io/designer

[vivekhumnabad]

Any update on this issue please..