Why is ngmodel not working?

Question

Angular

I work in ionic
There is an input for entering a date with a two-way binding

<ion-datetime (ionChange)="validateBookingDate()"
                      [(ngModel)]="bookingDate"
                      displayFormat="DD MMMM YYYY"
                      pickerFormat="DD MMMM YYYY" ></ion-datetime>
      </ion-item>

When the date is entered, this function is triggered, which checks the correctness of the entered value, if it is incorrect, then the input value is replaced with an empty string

validateBookingDate(){
    if(this.product.booking.includes(this.bookingDate)){
      this.bookingDate = ""
      alert('товар уже забронирован на эту дату')
    }
  }

The problem is that if you immediately select the wrong date, then the variable is assigned an empty string, but the wrong date is displayed in the input, but if you first select the correct one and then the wrong one, then everything works as it should

Answer 1

Try passing null.this.bookingDate = null;