[ion-datetime angular v6] "jumping" values when using the value property and ionChange


when using the datetime component with the [value] attribute and ionChange to change that value the date-time`s value keeps jumping to the next day after user selection occured. It seems like the ionChange is in some sort of trigger loop when I set the value. See my implementation below.

        [value]="[value]="endDate > startDate ? endDate : startDate""

.ts File:

onDateChange(event) {
    this.endDate = event.value;

I am certain that it has something to do how the value property or ionChange work; but I am lacking of understanding how to fix it or what a possible workaround could be. I still want to set my value dependend on other date values.
It works neither with the apply buttons nor without buttons.

Cheers and thx in advance