@davis94 It sounds like there might be a program or extension interfering with the website's ability to load properly. Have you looked through your extensions and add-ons for anything you don't recognize? If something looks fishy, remove it.
You might even consider uninstalling Firefox, restarting your computer, and installing a fresh copy. Make sure you backup your passwords and bookmarks if you do.
3rd option would be to download a different browser that you can test the site with. Chrome, Opera Mini, Brave, Chromium, or Edge/Safari depending on your platform.
Hope this helps.