W3 TOTAL CACHE dynamic content stops wp-admin/customize.php from loading preview

The W3 TOTAL CACHE dynamic content (“mfunc” comment) stops wp-admin/customize.php from loading the website’s live preview.

<!-- mfunc  <?php echo W3TC_DYNAMIC_SECURITY; ?> echo date('h:i:s'); -->
<?php echo date('h:i:s'); ?>
<!-- /mfunc  <?php echo W3TC_DYNAMIC_SECURITY; ?> -->

<div class="first-banner-widget group">

							<!--mfunc <?php echo W3TC_DYNAMIC_SECURITY; ?>
								if ( is_active_sidebar( 'sf-first-banner-widget-area' ) ){
									dynamic_sidebar('sf-first-banner-widget-area');
								}
							-->

							<?php
								if ( is_active_sidebar( 'sf-first-banner-widget-area' ) ){
									dynamic_sidebar('sf-first-banner-widget-area');
								}
							?>
							<!--/mfunc <?php echo W3TC_DYNAMIC_SECURITY; ?> -->
						</div><!-- .first-banner-widget -->

https://wordpress.org/plugins/w3-total-cache/