Problem

When deleting comments in Jira, the Atlassian Assist app will try to delete them in the Slack thread associated. In case there are no Slack administrators related to the channel where the ticket is raised, comments made through Jira will not be deleted. Comments that were created through the Slack thread will be deleted. This is happening because deleting messages created by the Assist bot in Slack, it’s required a Slack admin token. In general, the only messages a user can delete are their own, unless they are a Slack admin.

Solution

At least one of the administrators of Slack needs to be added to the channel where you’re syncing requests between Jira and Slack. With this, the app will have access to the admin token to delete the messages according to what’s happening inside Jira.