I tried to generate a form dynamically because the amount of questions depend on an object and for me the error was fixed when I added ngDefaultControl to my mat-form-field.
<form [formGroup]="questionsForm">
<ng-container *ngFor="let question of questions">
<mat-form-field [formControlName]="question.id" ngDefaultControl>
<mat-label>{{question.questionContent}}</mat-label>
<textarea matInput rows="3" required></textarea>
</mat-form-field>
</ng-container>
<button mat-raised-button (click)="sendFeedback()">Submit all questions</button>
</form>
In sendFeedback() I get the value from my dynamic form by selecting the formgroup's value as such
sendFeedbackAsAgent():void {
if (this.questionsForm.valid) {
console.log(this.questionsForm.value)
}
}