Dynamic binding problem with 3rd party library directive

I’ve been trying to integrate angular-bootstrap-calendar with ionic framework. There seems to be some issues which I can’t seem to resolve. The example is in the codepen.io link below:

I notice that the events appear on the calendar when the ng-controller is in a directive that’s directly above the mwl-calendar i.e. in the example above, it’s the ion-content. The moment I move the ng-controller up to ion-pane directive, the events don’t show up in the calendar anymore.

The author of angular-bootstrap-calendar seems to think that this is a bug with ionic framework. How can dynamic binding work correctly with the ng-controller moved to the ion-pane directive?