Teams bot framework - composeExtensions does not display buttons on adaptive card - botframework

Question

Two compose extension commands are defined in the manifest. These trigger a request to bot framework, which responds with an adaptive card.
When the adaptive card is displayed, it's rendered correctly except the button is missing. If I send the exact same adaptive card as a chat activity, it displays correctly.
handleTeamsMessagingExtensionFetchTask Code
// enableInboundCard = below json
const card = this.renderAdaptiveCard(enableInboundCard, { channel })
return {
task: {
type: 'continue',
value: {
card,
height: 500,
title: 'Enable Inbound',
width: 600
}
}
};
Command (in manifest).
{
"id": "enableInbound",
"context": [
"compose"
],
"description": "Enable inbound SMS to channel",
"title": "Enable Inbound",
"type": "action",
"fetchTask": true,
"parameters": [
{
"name": "test",
"title": "test",
"inputType": "text",
"value": "test"
}
]
}
Adaptive Card
{
"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
"type": "AdaptiveCard",
"version": "1.5",
"body": [
{
"type": "TextBlock",
"size": "Large",
"weight": "Bolder",
"wrap": true,
"style": "heading",
"text": "Enable Inbound SMS"
},
{
"type": "TextBlock",
"text": "A wholeeeeeeee bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch bunch of txt",
"wrap": true
},
{
"type": "FactSet",
"facts": [
{
"title": "Current Channel",
"value": "${channel}"
}
]
},
{
"type": "ActionSet",
"actions": [
{
"type": "Action.Execute",
"title": "Enable Inbound SMS",
"verb": "enable_inbound",
"fallback": "Action.Submit"
}
]
}
]
}