Search form and result list in the same view

I have what ought to be a simple problem that is driving me nuts. I have an ion-view that contains a form to capture search criteria, and an ion-list to display the results. I trigger a search on the controller when the user hits search on the keyboard. This invokes an angular service that uses $http to get JSON data. In the promise .then() callback I then set that data on the $scope object, which is used then used to populate the ion-list via an ng-repeat on an ion-item. Like I said, very basic stuff.

What I have found is that while the service executes correctly and the resulting data gets set on the $scope correctly, The ion-list never gets updated. I have also found that if I remove the form from the view and invoke the search as the controller is initialized using some canned search terms, the list does render correctly. I thought maybe I was handling the response outside the normal $digest proccess, so I tried $scope.$apply(), but that complained about already being in a $digest loop.

Can anyone think of a reason that having both the form and list in the same view would be causing a problem? I should note that the form does not have a method or action and I am handling the submission through ng-submit.

Thanks for any ideas you might have on this.