Ionic select selected not working

Hi,

I have a ionic select that i fill with for cycle

<ion-select value="" ok-text="Ok" cancel-text="Annulla" formControlName="skill_level_id"
                       style="white-space: pre-line !important" value="7">
      <ion-select-option *ngFor="let skill_level of skill_levels" value="skill_level['id']">{{ skill_level['tcode'] }}</ion-select-option>
  </ion-select>

After I fill the select in my ts fill i make

this.skillForm.controls[“skill_level_id”].setValue(skill_level_id);

The problem is that if I open the select the value is selected but is not showing in the UI if I not open the select…
The are too many bugs…