I am not understanding Binance EARN.

From my $400 in binance earn.
I am expecting atleast $0.31 per day interest based on its the Estimated daily rewards.

But I notice with my total $599 EARN portfolio
it only earns $0.17 a day.. very far from the estimates..

Something is not right.
Someone please enlighten me why this happens? I know I am eligible for the Bonus Tier.