I have the JIRA Cloud Slack app successfully connecting a Slack channel to a JIRA project. When comments are posted on a ticket a notification is posted in the channel by the Jira Cloud bot.
Additionally, I have connected my Slack account and JIRA account. When I comment on a ticket and mention myself, the Slack notification has a Slack user tag for the comment poster, but not for the user mentioned.
@nick (tagged) commented on a Story in ToDo
XX-1 Test story
"@nick (not tagged) please update this ticket."
No sorry, we adjusted our workflow slightly to have users manually tag others in slack and to not rely on JiraBot.
A potential solution I've thought about but not had time to work on, is building a bot that listens for posts from JiraBot, parses them to see if anyone was tagged, and then either updates the message to fix the tag, or automatically adds a new message afterwards with the proper tags.