MS Teams Alert integration not working

We are trying to integrate Grafana into my organization’s MS Teams, followed this guide Grafana using Microsoft Teams. We’ve created a channel, added an incoming webhook and configured alerts in Grafana to MS Teams. But there is nothing happening when we are trying to test the alert. When we look at the logs from the Grafana box, we see the error below:
t=2020-02-13T04:25:03+0000 lvl=info msg=“Executing teams notification” logger=alerting.notifier.teams ruleId=1 notification=“MS Teams”
t=2020-02-13T04:25:32+0000 lvl=eror msg=“Failed to send teams notification” logger=alerting.notifier.teams error=“context deadline exceeded” webhook=“MS Teams”
t=2020-02-13T04:25:32+0000 lvl=eror msg=“failed to send notification” logger=alerting.notifier uid=8dl2ZkQWk error=“context deadline exceeded”
t=2020-02-13T04:25:32+0000 lvl=eror msg=“failed to send notification” logger=alerting.notifier uid=8dl2ZkQWk error=“context deadline exceeded”
t=2020-02-13T04:26:02+0000 lvl=info msg=“New state change” logger=alerting.resultHandler ruleId=1 newState=pending prev state=no_data

When we checked with the team that supports MS Teams in our company, he had us try to send a sample payload and the alert went in the channel in Teams. Might there be some issues on how the json body that the configured alert in Grafana is set up that is not compatible with what Teams expect? How do we fix that? Thanks in advance.