The website gets updated frequently so that can probably have some impact at times, it can also have something to do with browser issues, check add-ons that may interfere and always update your browser to current version available, also try delete history, cookies, etc. Your internet provider may also run maintenance at times and interfere with your connection, you can run a speed test to see if things are ok on that part.
If its a global thing then more people would probably complain about it so its probably going to be a browser issues, had same case in past and after cleaning up the issue was resolved.