Recently, I found out that submission verdict does not update in real time, in pages like problemset status. I mean, verdict stops at "Running on test X", and would not update automatically to something like "Accepted" or "Wrong answer".

Console in Firefox shows "Cross-Origin Request Blocked" then "can’t establish a connection": (The warning message is unclear, I'll copy it down here:

"Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://pubsub.codeforces.com/ev/8c9bc4287ed5c8013c8d556f014cb025c89ae4fd/03b84d6f1e21465e74ad2db61be76afcd8d9da3e?_=1534581570917&tag=&ti_me=&eventid=. (Reason: CORS request did not succeed)."

"Firefox can’t establish a connection to the server at wss://pubsub.codeforces.com/ws/8c9bc4287ed5c8013c8d556f014cb025c89ae4fd/03b84d6f1e21465e74ad2db61be76afcd8d9da3e?_=1534581571486&tag=&time=&eventid=.")

So I guess either pubsub.codeforces.com server is down, there is some problem with cross-origin request setting(I have little knowledge about front-end development so I'm not sure), or there is problem with my browser setting.

Did anyone also encounter similar problem? What is the real problem here and how can I solve it?