Angular 5 + materializecss Form reset - materialize

Question

I have a form for adding new users and I am having problems with the form reset because it does not remove the valid class of materialize.
The form:
<div class="col s12 m12 l4 xl4">
<form (ngSubmit)="onSubmit(); newLabMember.reset()" #newLabMember="ngForm" ngNativeValidate>
<!-- New lab member form -->
<div class="section">
<h5>Add lab member</h5>
<div class="input-field">
<input type="text" name="firstName" [(ngModel)]="user.firstname" class="validate" id="firstName" validate required>
<label for="firstName">First name</label>
</div>
<div class="input-field">
<input type="text" name="lastName" [(ngModel)]="user.lastname" class="validate" id="lastName" validate required>
<label for="firstName">Last name</label>
</div>
<div class="input-field">
<input type="text" name="email" [(ngModel)]="user.email" class="validate" id="email" validate required>
<label for="email">Member email</label>
</div>
<blockquote>An email will be sent to the new user with a password and further instructions.
</blockquote>
<div class="input-field">
<button type="submit" class="waves-effect waves-light btn blue-grey darken-1">Add new member</button>
</div>
</div>
</form>
</div>
As you can see, when I submit the form I use reset() form but the class .valid from materialize still there.