I have configured notification rules for AWS CodePipeline to send notifications to Slack channels and these were working for the past 4 months and suddenly stopped working today. I tried to troubleshoot the issue using this link but couldn't resolve it so far. Any help would be highly appreciated. Thanks!
Note: Even AWS Chatbot is able to send test messages to channels and SNS Topic is also able to push notifications to the Email endpoint. I suspect that there is some issue with this HTTPS endpoint.