A "reward period" is a defined timeframe where LeoDex allocates USDC from affiliate fees to sLEO stakers — the current period paused on 3/24 with no new one announced yet. You're right that the daily USDC distribution has been minimal (often under $1 total split among all stakers) despite a large accumulated pool — the team hasn't publicly explained the low allocation rate or the 12K-15K USDC sitting idle.