[Plugin: NextGEN Gallery] Imagebrowser AJAX mode not working

Great plugin, Alex. I use it on every WP site I do. One small question: I keep reading that the imagebrowser mode now has AJAX mode so that the page doesn’t refresh. But here is an example on my site:

https://yongworldwide.com/products/exhibits/

The AJAX isn’t working. I have the “Enable AJAX pagination” box checked under Options–Gallery. Do I need to do anything else? Here is my code for imagebrowser.php:

<div class="pic"><a class="ngg-browser-next" id="ngg-next-<?php echo $image->next_pid ?>" href="<?php echo
$image->next_image_link ?>"><img alt="<?php echo $image->alttext ?>" src="<?php echo
$image->imageURL ?>"/></a></div>
	<div class="ngg-imagebrowser-nav">
		<div class="back">
			<a class="ngg-browser-prev" id="ngg-prev-<?php echo $image->previous_pid ?>" href="<?php echo $image->previous_image_link ?>">◄ <?php _e('Back', 'nggallery') ?></a>
		</div>
		<div class="next">
			<a class="ngg-browser-next" id="ngg-next-<?php echo $image->next_pid ?>" href="<?php echo $image->next_image_link ?>"><?php _e('Next', 'nggallery') ?> ►</a>
		</div>
		<div class="counter"><?php _e('Picture', 'nggallery') ?> <?php echo $image->number ?> <?php _e('of', 'nggallery')?> <?php echo $image->total ?></div>
		<div class="ngg-imagebrowser-desc"><p><?php echo $image->description ?></p></div>
	</div>

Thanks!