Why does the mobile version freeze with fullpage.js?

Question

JavaScript

There is a site savvas.tech , the full version of the site opens normally, tests all show good speed. If you open it on a mobile phone, it doesn’t turn on for a very long time, as if it doesn’t respond, when you scroll down, it can freeze, underload, slow down. If you check in the developer tool, then everything is fine. When the page is reloaded (in incognito mode), it opens instantly. The site uses the fullpage.js plugin, I suspect that it is to blame for something, but I don’t understand why, help.
Thanks