When payment going through get error processing the payment message

When buying gift card, having issues.

Into checkout all fine and when went to process payment it goes through to the bank (and get confirmation on phone). But on the site there is a long period of delay on the site and eventually get the message below saying

There was an error processing the payment: There was a problem sending a request to the Stripe API endpoint.

The API key in the WooCommerce settings is fine as we have non-gift card products and those orders and payments going through fine.

Client has checked on Stripe and bank and all fine, payment taken out/received and notification comes through on phone.

But they get email from web site to say order failed. And checked in WP Admin, can see the order status is failed.

On the log in WooCommerce (in Status->Logs) there is a Stripe API error.

Says something like Error Stripe API error: GET charges/py_123abddqwthdkd

So payment goes through but looks like issue with site connecting with Stripe and getting back to info that payment received etc.