The issue is present in 1.30.0-wmf.4.

The screenshot is an illustration of the following scenario:

1. On any Flow board click to Thank some users in one post - all clicked 'thanks' will change to 'thanked'.
2. In the same post click on any Reply and after typing in the post, save the post.
3. All previously displayed 'thanked'' will changed to 'thank'.

Note:

• 'Thanked' changes to 'Thank' when a topic title or a summary are edited. Editing a board description does not affect the status of 'Thank' action.
• No duplicate notifications are sent.