We've created basic automation that grabs a selection of tickets in a specific status, and posts that list to a slack channel each week. No matter how the slack message is configured, even using the out of the box templates from Atlassian, it's duplicating the slack message.
Automation Configuration:
1. When:Scheduled(Uses JQL)
2. Then: Send Slack Message
Here are the tickets that will be released this Tuesday!
{{#lookupIssues}}
* {{key}} {{summary}}
{{/}}
This results in two identical messages being posted in slack.
"Here are the tickets being released this Tuesday
*issue one
*issue two
*issue three"
"Here are the tickets being released this Tuesday
*issue one
*issue two
*issue three"