GitLab

Reproduce:

let form = FormBuilder.group({
  name: [],
  values: FormBuilder.Array([FormControl(), FormControl()])
})

<form [formGroup]="form">
  <input formControlName="name"> 
  <ngsb-form-error-msg formControlName="name"></ngsb-form-error-msg> <!-- works -->

  <ng-container *ngFor="let ctrl of form.get('values').controls; i=index;" formGroupName="values">
    <input [formControlName]=i>
    <ngsb-form-error-msg [formControlName]="i"></ngsb-form-error-msg> <!-- doesn't works -->    
  </ng-container>
</form>