Your website's menu doesn't work. theme.js is replacing the browser's click listener on each of the menu a tags with a call to the "smoothScrolling" function. That function scrolls the page down to an element that has a "name" attribute that matches the hash, but you've used id attributes on them instead.

FYI you could replace that entire block of code with "html { scroll-behavior: smooth; }" in your site's CSS and get the same effect without needing any JS code at all.