GameCenter not refreshing

Question

There is a problem here when I use GameCenter. (By the way, I'm using sandbox mode.)

I update A score on A-device and B score on B-device. I can only see A score on A-device B score on B-device.

I can't always see other people's score, sometimes I can but sometime can't. Is that a GameCenter problem?

If it is the problem of GameCenter itself, Is there any suggestion way for Game leaderboard?

Answer 1

Thanks to Bob Gilmore, your answer are quite right I thinks. GameCenter did refresh after two or more user update their score. In order to refresh GameCenter, the threshold are likely to be three or four user.