I understand that, so you are telling me Slushpool isn't doing this on purpose? I'm just trying to get down to why it happened so suddenly out of the blue.
not sure what you mean when you get "6.5-7" coins per your 18TH...was there a period of bad luck on the pool? Remember the pool has to find blocks before you get paid, if they find less blocks...it takes longer to reach your payout.
6500 or 7000 satoshis per reward/block. I understand how mining works.