Buggy puzzle

lichess.org/training/QojNy
Black is supposed to have a rook but it was hidden when I tried it.

Anyone else have this problem?

I can see the rook, and also the previous traded rook, try refreshing the page.

@Tyronaught

If your network was lagging, or you ping was high, then the page may not load completely. Check out; Lichess.org/lag

It seems to be working now. I refreshed the page a few times when the problem existed and it remained hidden on those occasions. Was on mobile at the time. That it could be lag for that period is quite shocking.