Angular ui-select doesnt work on ion-view or ionicModal, only works on ionicPopup

<ui-select name="org" ng-model="" theme="selectize" class="form-control ng-pristine ng-invalid ng-invalid-required" style="margin-top: -5px; margin-left: 7px;" required>
   <ui-select-match placeholder="Organization Name" focus-me="true">{{$}}</ui-select-match>
   <ui-select-choices  repeat="item in rea_list | filter: $ |limitTo: 20" position="down">
         <div ng-bind-html=" | highlight: $"></div>

When i put this code on an ionicPopup, i can scroll the list of options to view the 20 options in the list but if i put this code on my ion-view on a page or in an ionicModal, i cant scroll through the 20 options.

I have no clue why this is so and I cant figure out a way to solve it too. It works perfectly on web but it doesnt work on mobile device.