A particular visitor may be directed to your site by multiple affiliates. Who should you give credit to if that visitor makes a purchase? The first referrer, the last referrer or anyone in between? Generally, the last referrer is given credit for the sale.
To consider the most recent referrer, go to Advanced settings in WC Affiliate settings and then enable the feature of “Allow overwrites”. Finally, click on the Save button.
If you do not check this option, the first referrer during the attribution window will be given credit for the sale.