but if it has been paying under expectation every week for more than 10weeks, there is a big problem.

I received 86% of my expected payment this past Saturday night.  That comes out to about 6/7ths of my expected payout, or one day of theoretical pay missing.  I know that the payments can vary slightly from week to week, depending on payout time.  For example, in some weeks, I received slightly more than the theoretical payment to make up for getting a little less the week before (less than 1% difference).  The payment has never been off by 14% though.