I too now get the 'server is for low pings only' every time i try to connect to gon, but not to overseas servers where my ping actually is high. In regards to when this started happening: A few months ago i woke up and gon #1 server was offline in qtracker, so i refreshed all servers again and noticed the gon IP address had changed, along with a few other things, like map cycle changed, voting was enabled for 38 hours then disabled. Nothing has changed on my end and my pings are still under 50ms as always, even in the worst congested periods, even whilst saturating my bandwidth to 99.9% with torrents (on purpose for testing), naturally, due to my low ping, fast net speed, 1ms jitter, being with node and being so physically close to the server.
All was fine, for years, then oneday it just started doing it. Im still a little sus on gon as my ping to gon is roughly the same as it is to any sydney server (over an extra 1000Km away and not node server). Im 'fairly sure' i should have a lower ping to gon server than anybody in sydney, especially considering its only 4 hops for me, and that includes my router and local exchange (4ms between them), and it is, just not in-game(and yes i partially know why, but nothing can yet explain the full extent of it). If i ping gon or ANY internode website my ping is always under 20ms, but always at least double in-game.
For now, i just have /reconnect bound to my F8 key, which works fine, only ever have to press F8 once, but i would like to know why it started happening out of the blue for alot of people, just out of curiosity. Maybe, alot of our internet connections simultaneously and magically deteriorated overnight in such a way that it only affects a few urban terror servers but no test known to mankind can produce any results that would explain it. I know it sounds silly, but its far more plausable than anything i've heard so far. Nevertheless, a minor bug, with an easy simple workaround but no explanation.