[ttasdasda]

I highly doubt it has anything to do with my host's ddos mitigation. Like abdulsami34 correctly pointed out, I can join the server as soon as I restart it (but can't join other servers running on the same machine). Also, getting UDP-blocked results in "retrying connection to xx.xx.xx.xx", while in this case, I don't get any errors at all. My connection to the server gets initialized, console starts spewing its usual stuff, and then it's suddenly over.

I can also contact the server just fine via other means (be it ssh, rcon or simply pinging it). The only thing that MIGHT get blocked is the server's connection to the master server of steam. I could try blocking it to test if it reproduces this effect, but I don't know what port is used by SRCDS to connect to steam.