An issue disappears on a scrum board after it is updated twice in a background thread via a Jira plugin

An issue disappears on a scrum board after it is updated twice in a background thread via a Jira plugin via Jira public Java API. To demonstrate it I prepared a simple example plugin (see attached zip file). You may run it with atlas-run and go to “Come here” → “Follow to me” on the top menu. There you will find out additional instructions about how to make an issue disappear. Any manual change on the Issue page (e.g. update the status, a new comment, etc) brings it back on the board.

What’s wrong there? Why issue disappear? How to update the issue via Jira JavaAPI (like I do in my plugin example) and do not let it disappear?

The plugin example is on my Google Drive as well as a short video demonstration.