Webhook Messages are not delivering New Relic Notifications

We integrated New Relic Notifications to Teams Via Webhook and the notifications started failing randomly with error  "Webhook message delivery failed with error: Microsoft Teams endpoint returned HTTP error 400 with ContextId 01=2"

The notifications are failing randomly whenever a new alert is in activated state . No notifications are failing when the state is changed to closed. 

JSON Payload : 
 

{
    "type":"message",
    "attachments":[
       {
          "contentType":"application/vnd.microsoft.card.adaptive",
          "contentUrl": null,
          "content":{
             "$schema":"http://adaptivecards.io/schemas/adaptive-card.json",
             "type":"AdaptiveCard",
             "$data":{
              "age" : "17"
             },
             "version":"1.6",
             "body":[
                {
                  "type": "Container",
                  "items": [
                    {
                      "type": "TextBlock",
                      "size": "Large",
                      "weight": "Bolder",
                      "wrap" : true,
                      "text": {{ json priority }},
                      "color": "Attention"
                    },
                    {
                      "type": "TextBlock",
                      "weight": "Bolder",
                      "text": {{ json annotations.title.[0] }},
                      "wrap": true
                    },
                    {
                      "type": "FactSet",
                      "facts": [
                        {
                          "title": "Alert State",
                          "value": {{ json state }}
                        }
                      ]
                    },
                    {
                      "type": "Image",
                      "url": {{json violationChartUrl}},
                      "altText" : "Image missing",
                      "style" : "default"
                      
                    },
                    {
                      "type": "FactSet",
                      "facts": [
                        {
                          "title": "Incidents",
                          "value": {{json totalIncidents}}
                        },
                        {
                          "title": "Impacted Entity",
                          "value": {{json entitiesData.names.[0] }}
                        },
                        {
                          "title": "Condition",
                          "value": {{ json accumulations.conditionName.[0] }}
                        },
                        {
                          "title": "Policy",
                          "value": {{ json accumulations.policyName.[0] }}
                        }
                      ]
                    }
                    
                  ]
                }
              ],
              "actions": [
                {
                  "type": "Action.OpenUrl",
                  "title": "Open Alert",
                  "url": {{ json issuePageUrl }}
                }
              ]
          }
       }
    ]
}