Problem with ng-if and angularjs how solution

Question

I have a problem between angularJS and select2 every time there is an ng-if select2 simply does not enable the search. I saw only one report of this fault but without solution.

 <section class="form-group">
            <label for="assunto" class="upper">Assunto:</label>
            <input type="text" class="short_field form-control upper pr" id="assunto" name="protocolo.assunto"
                ng-model="protocolo.assunto" ng-if="protocolo.isDisabled">
            <select id="assunto" class="form-control filter pr" ng-if="!protocolo.isDisabled" ng-model="protocolo.assunto">
                <option ng-repeat="a in assuntosDepartamento track by a.cod_ass" value="{{a.cod_ass}}">{{a.nome}}
                </option>
            </select>