Stripe Gateway Handling

That charge and payment intent webhooks would be the most important. We don't process payment_method.attached. Try using the Resend button on the charge webhook and see if that pushes it through. If not try with the payment intent webhook.

I've confirmed the webhook is working as expected and it does say it was sent successfully from Stripe dashboard. I checked it as you suggested and got a blank page.

Try resending the charge and/or payment intent webhook and see if it arrives.

I've just now resent the charge.succeeded & payment_intent.succeeded.

I don't see anything different but you can check in case I'm missing something.
 

I also checked the webhook URL against the one in our Stripe gateways via CBSubs, it is exactly correct & we've never made any changes to that as it has always worked. Could it be something to do with the API version?

Could it be something to do with the API version?

Possibly, but I can't see what. You've a successful Stripe payment just days before this one. For now I suggest manually activating their subscription since they have confirmed paid. You can force it to renew by editing them in CB > User Management.

What payment method are they trying to pay with? It's very strange for just 1 payment to fail while others aren't. I don't really have any other suggestions. CBSubs Stripe is currently very different from what you're using as I've completely redesigned it to use latest APIs so it's possible it's an IPN handling issue already fixed.

Looks like they used a vis prepaid card & passed everything via Stripe. I will update it manually for now.

If memory serves correctly, I updated to the latest version of CBSubs on the 3rd, so that payment could've been completed just before the update was completed.