I’m wondering why CIS Firewall is blocking this connections on my browser.
I have noticed that this behavior blocks for example, communications in Discord.
The rule for Brave is “Web browser”
What’s the reason for this behavior and why is it getting blocked?
It’s QUIC protocol created by Google. Basically its standard encrypted web traffic over the UDP transport layer instead of TCP, because it has less overhead for servers.
Its blocked because its not part of the Browser Rule since its a fairly recent protocol (2012). Just edit the default Browser rule to Allow outgoing UDP request over port 443.