My friends and I updated our Realm to 1.17 proper. When we first got on, it worked just fine for 10 or 20 minutes. And then, the server Timed Out all of the players. Reconnecting took a long time. When we reconnected, the world had automatically been rolled back to how it was when we first updated it to 1.17. This may be a server load issue, or a 1.17 crashing issue, I don't know.

And it did the same thing a second time soon after we got to reconnect, and we've been trying to reconnect a third time for several minutes.