Keyword not popping up when onfocused input field

I am new to angular/ionic4.i have created the input field when it is focused the keyboard is supposed to be popup but it is popping up only for android only when u again tap in the input field even after the field is focused but for ios is not popping up at all

<ion-input type="input" placeholder="Enter your first name" [readonly]="isReadOnly" name="profile" [value]="firstName" #nameCtrl="ngModel" ngModel pattern="[A-Za-z]+" minlength="3" maxlength="20" [(ngModel)]="firstName"  #name no-padding>
</ion-input>