[ttasdasda]

Tried blocking both UDP and TCP traffic to and from 26900, no effect, I could still connect to the server just fine. Moreover, I captured the traffic for a minute using tcpdump and could't even find any traffic using this port during normal gameplay.
I'm led to believe this problem has nothing to do with ddos mitigation, it seems more and more similar to the "failed to join session" error that used to plague CSGO for years.