Hello,
You can simply remove the .slider-parallax Class from the #slider Container and the .slider-parallax-inner Container from the #slider Container to disable this effect.
Additionally, Please remove the following code from your page since it is not required:
$(document).ready(function () {
//initialize swiper when document ready
var mySwiper = new Swiper ('.swiper-container', {
// Optional parameters
parallax: false,
})
});
Also, make sure that you always add Inline JS Codes at the bottom of the Page, after the js/functions.js JS File linking.
This will definitely fix your issue. Let us know if we can help you with anything else or if you find any further issues.