Left header button shows no visual feedback


I have a simple sub-header bar with a title for a date, and arrows on the left and right, meant to navigate forward and backward through days. Here is the code:

<ion-header-bar align-title="center" class="bar-subheader">
    <button class="button button-clear"><i class="icon ion-chevron-left"></i></button>
    <h1 class="title">Oct 30</h1>
    <button class="button button-clear"><i class="icon ion-chevron-right"></i></button>

The right button appears clicked when you press it; however, the left button does not give any visual indication of being clicked. I have tested if it functions by assigning a click-handler to it, and it does indeed call the click-handler, but it simply does not provide any visual feedback when clicked.

Any ideas what’s going on?