not rotating

hi,

Slider widget displays (sort of) ok but won’t rotate.
TypeError: jQuery(…).bxSlider is not a function

Javascript problem? slider js loading too soon? Tested on vanilla wordpress 4.4.2, twenty sixteen theme, all other plugins deactivated. also tested on custom ‘flat bootstrap’ child theme, same issue.

default (reset) option set via widget shows all testimonials with rotate speed at default.

var tw_4 = null;

jQuery(document).ready(function() {
tw_4 = jQuery('.testimonials-widget-testimonials4').bxSlider({
adaptiveHeight: false,
auto: true,

autoHover: true,
controls: false,
mode: 'vertical',
pager: false,
pause: 3000,
video: false,
slideMargin: 2,
slideWidth: 0
});
});

this plugin has worked great for me in the past but it don’t want to roll now 🙁

https://ww.wp.xz.cn/plugins/testimonials-widget/