For all financial information please open a Seller Store Support 1:1 Enquiry
Besides the date differences between dates of a financial report and Sales Summary One is based on downloads and the Financial report is based on money received is recognized.
It may take up to three months before the payment amount is recognized as sales depending on the payment options, and because of this, the sales amount stated in the sales summary may not actually be recognized as your sales of the month.
A Watch seller reported here that GSS had an error where coupons were counted as sales and corrected later. I did not verify that as it seemed to have been corrected.
Again any question of finances should go to the Seller Portal one on one support.
Samsung Developer Relations