The fact that it's 30 minutes exactly is a big clue, I think.
When you say 30 minutes exactly - when does it reset? When does it start counting?
For example, if you DC at 1:45, wait a few minutes, then reboot the computer and reconnect - do you get DC'ed at 2:15, or 30 minutes after the computer finished rebooting, or 30 minutes after you reconnected to RO?
How exact is the timing? 30 mins +/- 0 seconds is clearly something intentionally DCing you.
After yesterday's maintenance, this is happening to me again!! It was such a luxury when there was no disconnection at all!!
i got disconnected every 30 minutes again!!