ML Slider doesn’t work with jQuery update plugins

WordPress’s bundled jQuery is severely out of date. I have tried to update jQuery to the latest version using these three plugins:
https://ww.wp.xz.cn/plugins/jquery-manager/
https://ww.wp.xz.cn/plugins/jquery-updater/
https://ww.wp.xz.cn/plugins/version-control-for-jquery/

After installing and activating each of the plugins I get the same error:

$(...).flexslider is not a function

With a couple of those plugins you can choose a specific version of jQuery and even when I choose the same version that’s bundled with WP I get the error, so my guess is that it has to do with deferred loading or some other timing issue. However everything looks legit to me (see below), so I’m at a loss for a solution.

jquery.min.js loads at line 55:

<script type='text/javascript' src='https://code.jquery.com/jquery-3.3.1.min.js?ver=3.3.1' defer='defer'></script>

flexslider.min.js loads at line 597:

<script type='text/javascript' src='/wp-content/plugins/ml-slider/assets/sliders/flexslider/jquery.flexslider.min.js?ver=3.14.0' defer='defer'></script>

slider code begins on line 598:

<script type='text/javascript'>
var metaslider_4473 = function($) {$('#metaslider_4473').addClass('flexslider');
            $('#metaslider_4473').flexslider({ 
                slideshowSpeed:6000,
                animation:"fade",
                controlNav:true,
                directionNav:true,
                pauseOnHover:true,
                direction:"horizontal",
                reverse:false,
                animationSpeed:600,
                prevText:"<",
                nextText:">",
                fadeFirstSlide:true,
                slideshow:true
            });
            $(document).trigger('metaslider/initialized', '#metaslider_4473');
        };
        var timer_metaslider_4473 = function() {
            var slider = !window.jQuery ? window.setTimeout(timer_metaslider_4473, 100) : !jQuery.isReady ? window.setTimeout(timer_metaslider_4473, 1) : metaslider_4473(window.jQuery);
        };
        timer_metaslider_4473();
</script>

Has the plugin been tested with the jQuery update plugins listed? Is there another method I could use to upgrade jQuery that would work with the ML Slider plugin?

Thanks.