Unable to get `ctx.results` values in trigger action

We are using Aiven OpenSearch service for our logging/monitoring solution.
In OpenSearch Dashboard, we have configured an alert to send a Slack message whenever a timeout is detected in the logs with details relevant for next action to the team.

However, the Trigger Action preview message and also the triggered message sent to Slack both are empty for the details which we are looking for.

Attached screenshots of the concerned issue.