Couple of things to try.
1) Clear your cache. Close and reboot (reopen) your browser. Yeah, it's basic, but it solves a lot of problems.
2) If that doesn't work, follow the steps here:
https://us.forum.elvenar.com/index.php?threads/lots-of-game-lagging-complaints.28387/post-229653
Before you do, though, just fyi: there's a solar flare today and if you access the internet via satellite system, that's going to affect you. Your ISP might be sacrificing high... the word I want isn't coming to me. Energy isn't right, but sites that use a lot of bandwidth? I think that's what I'm trying to say - they might be sacrificing access to those sites, so online gaming might not be possible until they've dealt with whatever problems the solar flare caused/is causing.
But if you don't access via satellite, that might not be a concern for you at all.