jquery ui datepicker is not showing Month and Year in dropdown list
<p>(<a href="https://jqueryui.com/datepicker/" rel="nofollow noreferrer">https://jqueryui.com/datepicker/</a> - version 1.11.4)</p>

<p>It is still working fine and let user pick up the date but only problem is that the "Month" and "Year" are not showing up until you hover the mouse on it:</p>

<p><a href="https://i.stack.imgur.com/3V6kp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3V6kp.png" alt="enter image description here"></a></p>

<p>What can possibly cause problem here? I checked the browser's developer tool and there is not error or warning</p>