Why steemit post's author payouts are misleading/miscounting?

Hello steemit family,

I posted an article 15 days ago in blog, everything is good and the payout value is around $16 by the end of the 7th day. But the problem i got author payouts around $12.88 and curators payout is $3.30.

As per this I should get the author payout value in terms of steem power and steem dollars which equal to $12.88. But the thing is i only got 6.440 SBD and 1.985 STEEM POWER which are equal to just $8.425 but not $12.88.

My question here is where did my remaining $3.755 gone? I don't understand why is this happening? Previously it was not like that, I always used to get the exact amount of author rewards in terms of SBD and STEEM POWER.

But now author rewards counting became inappropriate and i lose more than 30% author rewards.

Can anyone explain me please? Why is this happening? Why steemit author rewards count became misleading. I will be very happy is anyone from the steemit developers answers my questions. Thanks in Advance.