Where did everyone's ratings and win/lose/draw records go while playing online? Is this a permanant data loss?

Yes, unfortunately it is a problem
It existed from a very long time ago, its not something new.
Basically the problem is if you've played a lot of games, at first there's no problem, it always increases when you win.

However, if you've played several dozen games online, for some reason or another a bug from Chessmasters 11 database online is causing problems recording your rating online.

That's the reason why Chessmaster 11 has its weakness when it comes to online play.

Everybody's got this problem online, your not the only one, so don't worry.

The win, loss and draw does record though, its just that when we lose, the rating always falls, when we win it doesn't increase.