Form validation when form spans multiple tabs - kendo-ui-angular2

Question

I have a form that spans multiple tabs in a TabStrip control. However, when the form is validated (e.g. f.valid), not all controls are considered when the validation is evaluated.
For example, if an input field is on tab 1 that is marked as "required" and the save action is called when the focus is on tab #3, the form will read as invalid since the required field is not in view. If the focus is on Tab #1, all works as expected.
I understand why this behavior is occurring, but I wanted to see if there was any suggested workaround.
Thanks!
Update
I created a plunkr that shows the basic issue. It is actually a little backwards from the problem I described, but it shows how the form ignores the fields on tabs other than the one displayed during validation: Plunkr Example
The template code looks like this:
<form #f="ngForm" (ngSubmit)="save(f)">
<kendo-tabstrip>
<kendo-tabstrip-tab [title]="'Paris'" [selected]="true">
<ng-template kendoTabContent>
<input type="text" name="controlOne" id="controlOne" [(ngModel)]="myModel.controlOne" required>
</ng-template>
</kendo-tabstrip-tab>
<kendo-tabstrip-tab [title]="'New York City'">
<ng-template kendoTabContent>
<input type="text" name="controlTwo" id="controlTwo" [(ngModel)]="myModel.controlTwo">
</ng-template>
</kendo-tabstrip-tab>
<kendo-tabstrip-tab [title]="'Tallinn'">
<ng-template kendoTabContent>
<input type="text" name="controlThree" id="controlThree" [(ngModel)]="myModel.controlThree">
</ng-template>
</kendo-tabstrip-tab>
</kendo-tabstrip>
<button type="submit">Save changes</button>
</form>
<div>
Valid when saving: {{ isValid }}
</div>