ng-repeat does not show blank values

I have the following code:

 <input type="search" class="form-control" placeholder="Busca por motivo" ng-model="search.motivo" >

<tr ng-repeat="item in vm.listaDesbloqueio | filter:search">
                        <td><input type="checkbox" ng-model="item.checkbox" /></td>
                        <td>{{item.data | date: "dd/MM/yyyy"}}</td>
                        <td>{{item.hora | formatTime}}</td>
                        <td>{{item.motivo}}</td>
                    </tr>     

But when I delete all the letters in the search field, I do not see the records with blank or null reason, would anyone know how to do so that the records with white or null appear in the subject?