Yes, it's a bug and everyone seems to be affected.
Your "real" ratings isn't lost, it's still in the leaderboard tab, but the matchmaking thinks everybody is level 38.75.
Since it's unclear how a rated game will evaluate (using your real ratings, or the fake 38.75), I'd suggest not playing rated games until this is fixed.
You can see if it is fixed when you look at the matching tab:
In the marked area to the right, you can see that it uses 38.8 as the basis to calculate the range of opponents that I want to match against. As long as it stays that way, the bug isn't fixed.