Bug in Amazon Aurora MySQL

This code on amazon aurora is producing rows where before it did not and I would like to know why

SELECT c._id AS Id FROM CustomersCustomersRMAs c WHERE ((c.Business = ?) AND (c.Customer = ?) AND ((c.ExpirationDate IS NULL) OR ((c.ExpirationDate IS NOT NULL) AND (c.ExpirationDate >= ?))) AND (((IF(((SELECT SUM(cr.Quantity) FROM CustomersCustomersRMAsItems cr WHERE (cr.RMA = c._id)) IS NULL), 0, (SELECT SUM(cr.Quantity) FROM CustomersCustomersRMAsItems cr WHERE (cr.RMA = c._id)))) - (IF(((SELECT SUM(cr.Quantity) FROM CustomersCustomersReceivingItems cr LEFT JOIN CustomersCustomersRMAsItems ccr ON (cr.RMA = ccr._id) WHERE (ccr.RMA = c._id)) IS NULL), 0, (SELECT SUM(cr.Quantity) FROM CustomersCustomersReceivingItems cr LEFT JOIN CustomersCustomersRMAsItems ccr ON (cr.RMA = ccr._id) WHERE (ccr.RMA = c._id))))) > 0)) ORDER BY c.EffectiveDate DESC