submenu dropdown not working IE 11

Hi i'm using bsnav for my website. there is some problem.

Chrome is fine but IE11 is not working when using the sub menu :(
Mouse hover function is working well in chrome, but not working in IE 11.

If you have IE 11 Browser, you can find issues in your site below link.
https://fitodac.github.io/bsnav/submenu-dropdown.html

Tell me any work-around this issues.