Ionic2 - ion-select(s) used without ion-item not working

I am trying to use following drop downs in my page

    <!-- Users Filter -->
            <ion-option value="All" selected="true">All</ion-option>
            <ion-option value="Admins">Admins</ion-option>
            <ion-option value="Blocked">Blocked</ion-option>
    < !-- Groups Filter -->
        <ion-option value="Groups..." selected="true">Groups...</ion-option>
        <ion-option value="G1">Group 1</ion-option>
        <ion-option value="G2">Group 2</ion-option>

I am getting into an issue while using these filters, as, I always see options from Groups Filter, even though I select User Filter??

If I enclose these select options into ion-item individually, it works … Can’t I use it without ion-item or I am missing something here …

finally, I made things work by using AlertController and Alert directly instead of using ion-select.

But, I still think, this seems to be a bug, what I have mentioned in my original post