Issue Summary

This is reproducible on Data Center: YES

There seems to be a regression in the 9.12.12 release, where adding a comment to a Jira issue on the Project Backlog page could result in duplicate comments.

Please see the attached video for the reproducer in 9.12.12.

Steps to Reproduce

1. Go to the Project Backlog page
2. Select a Jira issue and the right side panel shows issue details
3. Click on the bottom Comment text box to add a comment.
4. Repeat more than once, and on the second or third occasion, we will see two comment panels displayed.  
5. Type in a comment in one of the comment boxes, save it, and you'll create two duplicate comments in the issue.

I was unable to reproduce this in 9.12.1 but was able to reproduce it in 9.12.12. The customer reported that the problem occurred after upgrading from version 8 to 9.12.12.

Testings Done:

1. Unable to reproduce in 8.20.10
2. Unable to reproduce in 9.12.11
3. Able to reproduce     in 9.12.12
4. Unable to reproduce in 10.0.0

Expected Results

The Comment box expands, the user can enter a comment, and then save it. 

A single comment is saved.

Actual Results

The Comment box expands into two duplicate Comment sections. The user can enter a comment in one of the sections and then save it. 

Two duplicate comments are saved.

demo video

Workaround

Refresh the Backlog page and try to edit the Jira issue again.  It seems after a page refresh, the first comment attempt will correctly display one Comment box instead of two.