"Watchers" frame sometimes not displayed

Summary

Cannot add watchers via the count icon in some situations.

Steps to Reproduce

Situation #1

1. Edit a field through 'inline editing';
   Some fields will not cause the behavior (eg. Summary, Priority)
2. Click on the Watchers' count icon to add a new watcher;
3. Frame will not be displayed

Situation #2

1. Search for issues using the "Issue Navigator"
2. Set visualization to "Detail View"
3. Click on the Watchers' count icon to add a new watcher;
4. Frame will not be displayed

Situation #3

1. Search for issues using the Service Desk Agent's Queue
2. Select any issue in the queue
3. Click on the Watchers' count icon to add a new watcher;
4. Frame will not be displayed

Expected Results

JIRA Should display the "Add Watchers" frame below the Watchers icon

Actual Results

No frame is displayed

Workaround

Situation #1
Simply refreshing the page gets the feature working back again.

Situation #2
Open the issue on a separate tab/window (outside the "Issue Navigator") or use the More > Watchers link.

Situation #3
Open the issue on a separate tab/window to open the View Issue screen or use the More > Watchers link.