This is a bug of iOS 9, in my opinion it stretches from iOS 8, but came partially in version 9. If possible, you need to make a bug report. The bug is with input , which has the attribute readonly="readonly" . Selectric uses hidden input : 
What's happening:
- When you click on
selectric-wrapper , the _open method _open . - The
_open method _open focus to hidden input.selectric-input . I did not understand why this is done. It may be easier to hang the handlers for pressing the keys on the hidden item. And you can handle such events when the element is in focus. Why input ? If you use another element, then when you press the arrow keys, we will also scroll the document itself. Therefore, we used input , although I could be wrong. Maybe input better for readers, i.e. used it to increase accessibility.
And when the focus comes to input , despite the fact that it is readonly , iOS (I think so) is trying to allocate space for the keyboard. I can advise a simple workaround:
$(".selectric-input[readonly]").on("focus", function(evt) { this.blur(); });
Those. with the focus immediately get rid of him, because It’s impossible to move through the list using the keyboard, the functionality should not be broken.