Card_V2 display issue in Google Chat - google-apps-script

Question

I have the following JSON to display Card_V2 for Google Chat, (note: words with "let_" are variables):
{
"cards_v2": [
{
"card": {
"header": {
"title": "Create campaign",
"subtitle": "Please complete the following information",
"imageType": "CIRCLE",
"imageUrl": "let_avatar"
},
"sections": [
{
"widgets": [
{
"textInput": {
"label": "Campaign name",
"type": "SINGLE_LINE",
"name": "nCampaign",
"value": "let_campaign"
}
},
{
"textInput": {
"label": "Campaign subject",
"type": "SINGLE_LINE",
"name": "subject",
"value": "let_subject"
}
},
{
"textInput": {
"label": "User name",
"type": "SINGLE_LINE",
"name": "userName",
"value": "let_userName"
}
},
{
"buttonList": {
"buttons": [
{
"text": "Create campaign",
"color": {
"red": 0.502,
"green": 1,
"blue": 0.733,
"alpha": 1
},
"onClick": {
"action": {
"function": "create",
"parameters": []
}
}
},
{
"text": "Cancel",
"color": {
"red": 0.502,
"green": 1,
"blue": 0.733,
"alpha": 1
},
"onClick": {
"action": {
"function": "cancel",
"parameters": []
}
}
}
]
},
"horizontalAlignment": "CENTER"
}
]
}
]
}
}
]
}
My problem is that the "textInput" screen does not appear, but last week it did. Does anyone have any idea what's going on?
PS: the Card is the return of the onMessage(event) function in Google Apps Script