Web socket connection error

I get this message on the bottom corner when I am log on the web interface

on other threads u said I can be the firewall blocking the connection but never said what port, can you be more clear on that this ?

Websocket uses same port is the rest of the web app.

hmm strange

Often specifically WebSocket connection is blocked by some security software on corporate networks or by your internet provider.

atm i am on a personal PC and at home, gufw dont show anything strange so it can be my ISP, thx for all the help