Cross-browser problems

I have designed a website using WordPress and caching it with W3 Total Cache. I have experience with them both but I encountered the next problem.

The website https://atelieruldigital.com is a one page website, with another page for the partners of the program (https://atelieruldigital.com/parteneri/). When I access the partner page, everything loads as it should. When I access the main page by clicking “Acas?” or the logo, I have the next behaviors:

> Google Chrome: everything loads as it should;
> Mozilla Firefox: the scripts have lots of errors in the console and the page loads broken. I have to refresh (F5) to make it work as intended;
> Microsoft Edge: the same problem as Mozilla.
I am using manually minifying, only by combining the scripts, excepting the mobile-menu.js, which grants error when I try to combine it. I do not use page caching, only object and browser caching. The theme is a custom theme, based on Twenty Sixteen.

If I disable the caching plugin, everything works as intended. But I need it to help the page load faster.