When Jira Cloud sends a Slack notification for a comment that contains a user mention and the comment author is "Automation for Jira", the mention appears in Slack as the internal Jira account ID (for example @712020:xxxxxxxxx) instead of a readable @username.

Steps to Reproduce :

• In Jira Cloud, configure the Jira Cloud for Slack integration so that Slack channel receives notifications when comments are added to issues in a project.
• Create an Automation rule in that project:

  1. Trigger: Any event that creates/updates an issue (e.g. "Issue created" or "Issue transitioned").
  
  2. Action: Add comment. In the comment body, include a Jira user mention, for example by typing [~accountid:712020:xxxxxx]
  
  3. In the rule's Actor / Run as setting, ensure the rule is running as: Automation for Jira (the default automation user).
  

• Publish the rule.
• Trigger the rule so that it adds the comment with the user mention.
• Observe the resulting Slack notification in the configured channel.
• For comparison, go to the same Jira issue and manually add a comment with the same user mention (using your regular user account) and observe the Slack notification for that manual comment.

Expected Result :

• For comments created by Automation for Jira, the Jira Cloud → Slack integration should resolve user mentions the same way as for manually created comments.
• Slack notifications should show user mentions as readable usernames, e.g. @username, not internal account IDs like @712020:xxxxxxxxx

Actual Result :

• For the Automation-created comment (actor = Automation for Jira): Slack notification shows the user mention as the raw Jira account ID, for example: @712020:xxxxxxxxx
• For the manually created comment (author = normal Jira user) with the same mention: @username

Workaround :

Change the Automation rule actor to a real user

• Open the Automation rule in Jira.
• Go to Rule details.
• Under Actor / Run as, change from: Automation for Jira to either: "User who triggered the event", or A specific user.
• Save and publish the rule.
• Re-trigger the rule and check the Slack notification.