Ranks used to be visible in the thumbnails on the Home page, Profile, and Games page, but today they are gone. I know there is a way to hide ranks, but I don’t think I did that accidentally, because the ranks are still visible in the list view of games.
Is this a bug? I notice that the disappearance coincides with the implementation of rengo, so I am wondering if that is the cause.
It is indeed the case, GaJ is already looking into it:
Should be fixed now
(note: Rengo games still don’t show the rank.
This is a feature - it helps identify rengo games in the list.
Just kidding. It’s a silly little thing that needs to be fixed, but forming the player-rank-number-of-players string sounds trivial but isn’t quite … will be done in due course)
Oh no! Now all OGS players are being shown as having a rank of 6k in the thumbnails.
Darn 
I need more test games in beta!
(Fix submitted)