AngularJS - Why doesn't initialized field pass validator?

Question

Angular

Hello. As a result of populating fields with an asynchronous request of form fields, several fields return a required error on submit (fields are filled with the correct data)
Form field (using mdp-datepicker with Material Design interface)

<mdp-date-picker mdp-placeholder="Date *" mdp-format="dd, MMM DD, YYYY" mdp-open-on-click required
                                         name="Date"
                                         ng-model="vm.models.date">
                        </mdp-date-picker>
                        <div ng-messages="vm.editForm.Date.$error" ng-if='vm.editForm.Date.$dirty'>
                            <div ng-message="required" style="color:red">Date is required</div>
                        </div>

When the controller is initialized, the correct data enters the form and is correctly displayed in the corresponding input.
This fragment returns false for the given field, in particular, we are talking about required

if(!vm.editForm.$valid){
//код обработки формы
}

Previously, everything worked fine as long as the method for getting data from the server was located in the body of the controller. Moved the data acquisition logic to the factory and got this error. Tell me, please, in which direction to dig.