IOS Game Center Leaderboard not showing scores reported (sandbox)

Hi,

Problem:

1. I report my score to the leaderboard ( wich says its successful ) .

2. I go to see the leaderboard & no scores appear.

This is running the game on the sandbox account. I did click on the delete test data on iTunes connect.

Question:

Does the sandbox environment behave this way after you delete test data?

I want to know this to make sure that it is not a problem on my coding and just part of the expected behaviour of the Game Center sandbox after deleting test data.

thanks