As reported in many threads, including this one:
https://wordpress.org/support/topic/retu-redirect-url-not-working-reset_wp_cart1
I am also having this problem. I tried it with Receive IPN messages (Enabled) checked and a notification URL filled in; with Receive IPN messages (Enabled) checked, and the notification URL blank; and with 'Do not receive IPN messages (Disabled) checked, both with and without a URL. The URL I have specified to redirect to is:
http://saywardfutures.ca/become-a-member/thank-you-for-joining/
In all instances, the URL that it retus to is:
http://saywardfutures.ca/become-a-member/thank-you-for-joining/?reset_wp_cart=1
This generates a 404 error when it gets back to my website.
I also uninstalled the plugin (latest version) and then reinstalled it with the same outcome.
Would love some help here.
Thank you!
Terry
https://wordpress.org/plugins/wordpress-simple-paypal-shopping-cart/