"Prevent Cross-Site Tracking" is a privacy feature in web browsers designed to limit how advertisers and websites track your online activity across different sites.    

When enabled, it blocks cookies and other tracking methods used by sites to track your browsing. This means if you click from Cashrewards to a merchant website, the Cashrewards tracking scripts don’t work.   

This feature disrupts functionalities that rely on tracking and will make your purchases via Cashrewards ineligible for cashback.