Check All only checks the first item in a pane

[SteveDavis]

he 'check all'menu item only selects the first item in a pane.

Interestingly, this can be seen on the demo site, but only in the planning pane. Other panes appear to be working OK. In our example it appears to affect other panes too.

Could you please look to see if a fix can be coded which resolves the issue seen on the demo site? I suspect this will fix the issue we're seeing across all panes.