@mithunshanbhag When an Azure Monitor Action Group is defined to send a webhook to some complex endpoints such as Microsoft Teams or Slack, the webhook may complete successfully but the data is not received as expected by the target application. This is due to the endpoints are expecting the webhook payload in a format that is different than what is provided by Azure Monitor.
I have successfully reproduced the issue from my end by creating an activity log alert(with common-alert-schema enabled) which sends notification to Microsoft Teams by following this documentation ( attaching reference of Microsoft Teams notification). I believe, your endpoint is not receiving the data due to different format of payload. I would suggest you to kindly check on that.