It looks like a few things are going on that may affect other things. So, first you a 503 error and you have a CORS policy error:
Failed to load resource: the server responded with a status of 503 (Service Unavailable)
(index):1 Access to XMLHttpRequest at ‘https://pageview-notify.rdstation.com.br/send’ from origin ‘https://www.onixsecurity.com.br’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.
Both of those should probably be solved by your host.
Your theme also is presenting over 300 errors due to this:
Uncaught TypeError: Modernizr.mq is not a function
at fusion_side_header_scroll (main.min.js?ver=fd73e45167efa2164bbed22c9ef32ca6:1)
at dispatch (jquery.js?ver=1.12.4:3)
at r.handle (jquery.js?ver=1.12.4:3)
which seems to be coming from Avada / Fusion issues.
I would test to see if any plugins, and of course the theme, are causing a conflict which results in the rest of the errors and the functionality being broken.
1. Deactivate all of your plugins except Elementor and Elementor Pro. If this solves the problem, reactivate each plugin one by one, until you spot the problematic plugin. If found, contact that plugin’s developers for help, or use a different plugin.
2. Switch your theme (temporarily) to a default WP theme such as Twenty Fifteen to see if your theme is causing an issue. If so, contact the theme’s developers for help, or use a different theme.
3. Clear all cache (server cache, caching plugin, and browser cache).
