PayPal Shopping Cart - Purchase Completion Issue

[TomB]

Set Up:

Cart: JavaScript SDK
Buttons: Legacy Buttons (Add to Cart, not Buy Now)
Email: Merchants registered PayPal email address
PayPal ID: Using Sandbox ID but have also tested using Live Client ID
Sandbox: When using Sandbox have made sure checkbox for sandbox is checked / unchecked for live testing.
Version of minicart.js: Most current (21.1.0 - June 26, 2026) Older versions display the same issue.

The Issue:

Items selected are placed in the cart. Upon checking out the items are passed to the PayPal Java SDK popup. Customer selects pay by credit/debit card. Fills in all required fields. Clicks button slider to "Not Create Account". Clicks pay button, PayPal processes the order (spinning graphic) and returns customer to the success page on website. So far everything looks good. (Get the same results even if the customer logs into their PayPal account).

The problem is no emails are sent from PayPal to the customer or merchant acknowledging the purchase. The funds are never taken from customers credit card / PayPal account or posted to the merchants ledger.

Steps Taken:
PayPal Developer

Made sure PayPal Features have Subscriptions, Payment links and buttons, Payouts, JavaScript SDK v6 and Mobile SDKs all checked.

Checked for Notifications (email) Nothing there

Checked API calls under Event Logs - There are several with Date and time, HTTP status, Debug ID, Request Path, Error message
HTTP status shows a 201 OK and Request path shows POST /v2/checkout/orders

Checked to make sure the sites host server is not blocking port 443 (PayPals callback port)

Made a simple single item page with only the cart and 1 button set (same credentials) same results as the full page

Put the single item page on a different server - same results

Conclusion:

It's almost as if the scripts onApprove function is not firing the "intent" "Capture" to complete funding.

Any insights would be greatly appreciated.