Issue Keys are not rendered properly on Scrum work mode

Summary:

On the Work mode (Scrum board), If the first (top) swim lane is unfolded/expanded, the display is correct.
However, if user folds in the top swim lane, none of the Issue keys in any of the swim lanes below are displayed: they are shown as a hyperlink with 3 dots "..."

Steps to reproduce:

1. Go to JIRA Agile work mode that has more than 1 swimlane
2. Fold in the first swimlane
3. Unfold/expand the other swimlanes
4. The issue key will not be displayed. It will show ... (triple dots) instead

Additional Information

• Occurs in JIRA 6.3.6 with JIRA Agile 6.6.11, JIRA 6.3.9 with JIRA Agile 6.6.11
• This does not occur in JIRA 6.3.9 with JIRA Agile 6.6.0
• I changed the priority to Major due to the fact that it doesn't render ISSUE KEY properly.