RadDatePicker OnChange event is not working on iOS

Question

I have a DateOfBirth RadDatePicker that updates a Age field (textbox) when updated. This functionality is not working on iOS. One thing to note is that the Age field is readonly. But I don't think that's the issue, since I have removed readonly and it still behaves the same way.

Fields["DateOfBirth"].OnChange(Fields["Age"], (sender, e, target) =>
                {
                    TextBox txt;

                    txt = sender as TextBox;

                    if (txt != null)
                    {
                        this.SetFieldValue(Fields["Age"], user.AgeOnDate(DateTime.Parse(txt.Text)).ToString());
                    }
                });

This is in the base class: RadDatePicker dp;

                dp = new RadDatePicker() { Enabled = (!field.IsReadOnly && FormDisplayMode != FormDisplayModeEnum.Locked), EnableShadows = true, SelectedDate = null, DatePopupButton = {Enabled = (!field.IsReadOnly && FormDisplayMode != FormDisplayModeEnum.Locked)}, Calendar = { SpecialDays = { new RadCalendarDay() { Repeatable = Telerik.Web.UI.Calendar.RecurringEvents.Today, ItemStyle = { BackColor = Color.FromArgb(255, 207, 239, 207), ForeColor = Color.Black } } } } };
                
                if (field.ChangeActions.Count > 0)
                {
                    dp.SelectedDateChanged += new Telerik.Web.UI.Calendar.SelectedDateChangedEventHandler(dp_SelectedDateChanged);
                    dp.AutoPostBack = true;
                }