Slider script makes drop-down menu not show up

I have a website that includes two sliders. I found a script here on the forums which makes it so that one sliders controls them both.

This leads to the hamburger menu for tablet/mobile not work. The menu will show up for about 0.2 seconds and then close itself. If I remove the code from the custom code part of the settings, it suddenly works again.

Anyone have any idea why this is happening? And if I can solve it without removing the script?

The slider script does not work in the designer – so here is the link to preview the site:

I’ll also post the script I am using here:

Here is my site Read-Only: