Hovering Thumbnails not working

Hi

Mouse over thumbnails or click on thumbnail doesn’t work as it did in older versions.
I tested it down to version 3.5.7 without success. I checked it with different browsers and different devices and cross checked it with your demo-sliders (not knowing your settings) without any success. I’m quite sure that in previous times it worked well.
Maybe it depends on wordpress or something else. I didn’t get any console errors.
Please check your plugin.

Best Regards Michael

The page I need help with: [log in to see the link]