$returnURL sometimes called twice by SumUp

[purplespider]

I use the following to perform a checkout on my site:

        try {
            $sumup = $this->sumUpInstance();
            $checkoutService = $sumup->getCheckoutService();
            $checkoutResponse = $checkoutService->create($amount, $currency, $checkoutRef, $payToEmail, $description, $payFromEmail, $returnURL);
            $checkoutId = $checkoutResponse->getBody()->id;
            //  pass the $chekoutId to the front-end to be processed
        } catch (\SumUp\Exceptions\SumUpAuthenticationException $e) {
            echo 'Authentication error: ' . $e->getMessage();
        } catch (\SumUp\Exceptions\SumUpResponseException $e) {
            echo 'Response error: ' . $e->getMessage();
        } catch (\SumUp\Exceptions\SumUpSDKException $e) {
            echo 'SumUp SDK error: ' . $e->getMessage();
        }

When the provided $returnURL is accessed, the booking is marked as "Paid" and a confirmation email is sent.

However, it seems that sometimes SumUp will access this URL twice, at basically the same time, resulting in the customer receiving two confirmation emails (despite a check on if it's already been marked as paid).

Is this an issue on SumUp's side that is causing this duplicate callback to the $returnURL?

[entinio]

Did you find a way to avoid that double call? I exactly have the same problem right now. That return_url webhook is called twice instantly, making it complicated to handle with asynchronous functions.

[purplespider]

I may be wrong, but I think I did implement a workaround by calling the SumUp API when the confirmation page loaded, to instantly get the payment status meaning the payment got logged as paid at my end, before SumUp even made the double webhook call. I've since switched to Stripe.