Google Assistant not showing basic card when responding to action_intent_PERMISSION - json

Question

I have two intents defined on Dialogflow. Both use a webhook fulfillment implemented in php which returns json.
One of them is activated by the action_intent_PERMISSION event. If the user granted permission, it performs an action and returns both SimpleResponse (text) and a Basic Card with some text and an image.
The problem is that the Basic Card is never shown. In the debug tab of Google Actions Simulator, I can see that the Basic Card is present in the json sent to the assistant, I see it in the Response tab in simulator, but if I look at the Debug tab in simulator, the basic card is not listed under visualElementsList.
The other intent asks user for a zip code, and then performs the same action and returns the same json as the previous intent. In this case, the Basic Card is always shown and I can see it listed under visualElementsList in the Debug tab.
I can't find why the basic card is not displayed at all when the intent is activated by the action_intent_PERMISSION event. I have been researching and looking and can't find it. Thank you for any help.
This is the response tab in simulator for the intent that shows the basic card:
{
"conversationToken": "[\"closestitem\"]",
"finalResponse": {
"richResponse": {
"items": [
{
"simpleResponse": {
"textToSpeech": "The item is xxxxx"
}
},
{
"basicCard": {
"title": "Your Closest Item",
"subtitle": "The item is XXXX XXXX XXXX",
"image": {
"url": "https://www.example.com/image.jpg",
"accessibilityText": "Item"
},
"buttons": [
{
"title": "View More",
"openUrlAction": {
"url": "https://www.example.com/"
}
}
]
}
}
]
}
},
"responseMetadata": {
"status": {
"message": "Success (200)"
},
"queryMatchInfo": {
"queryMatched": true,
"intent": "XXXXXXX-2fd7-4ec3-9c88-d90cfccf8661",
"parameterNames": [
"zip"
]
}
}
}
This is the content of the response tab for the intent that is not showing the basic card. I need this basic card to be shown:
{
"conversationToken": "[\"closestitem\",\"closestitem-followup\"]",
"finalResponse": {
"richResponse": {
"items": [
{
"simpleResponse": {
"textToSpeech": "The item is XXXXXX"
}
},
{
"basicCard": {
"title": "Your Closest Item",
"subtitle": "The item is XXXXXX.",
"image": {
"url": "https://www.example.com/image.jpg",
"accessibilityText": "Item"
},
"buttons": [
{
"title": "View More",
"openUrlAction": {
"url": "https://www.example.com/"
}
}
]
}
}
]
}
},
"responseMetadata": {
"status": {
"message": "Success (200)"
},
"queryMatchInfo": {
"queryMatched": true,
"intent": "XXXXXXX-3c6d-44fa-b35d-6b097c3da054"
}
}
}
The Errors tab is empty in both cases in simulator.