Trigger ionChange when select value is the same

I have 1 ion-datetime and 1 ion-select. Based on what is selected for ion-datetime, it will call backend API to retrieve values for ion-select. The date selected can be the same, but based on the API submission timing, the date returned back can be different.

  <ion-item >
    <ion-label>Date: </ion-label>
    <ion-datetime class="dateInput" displayFormat="MMM DD YYYY"
      [(ngModel)]="dateList" (ionChange)="retrieveValues()">
    </ion-datetime>
  </ion-item>

  <ion-item>
    <ion-label>Values: </ion-label>
    <ion-select [(ngModel)]="valueList" (ionChange)="changeValue()">
      <ion-select-option*ngFor="let value of valueList" [value]="value">{{value}}
      </ion-select-option>
    </ion-select>
  </ion-item>

How do I trigger (ionChange)="retrieveValues()" even if the date selected is the same? Currently it only runs when the selected date is different from previous.