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":

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? How can the problem be solved?