I am testing Stripe in Test mode on our test website (over an http: insecure connection, in case that might be relevant). I am getting errors on the cart side but the Stripe Dashboard is showing that test payments (both Auth-only and as Auth&Capture) are fine.
The Stripe Dashboard shows the following under the Events and Logs detail for a transaction, e.g. :

--
Pending webhook response
A Checkout Session was completed
21/04/2022, 19:12:24
The payment pi_3Kr4TaJWPAht5EhN1jhFmedF for £356.90 has succeeded
21/04/2022, 19:12:23
--

(That one was for an Auth&Capture)

The "Pending webhook response" looks to be the cause of the issue, and I get the same for Auth-only, too).

The transaction detail for that outstanding webhook shows:

--
From Stripe
checkout.session.completed
View event detail
Pending webhook response
A webhook that is subscribed to the event hasn't successfully responded yet
--

The user side of the cart looks to have completed the purchase whilst within Stripe but then gives up, with:

Sorry, there seemed to be an error !

The items are still in the cart, even though the payment (or authorisation) has actually succeeded on the Stripe side.

We've spent ages looking into Stripe amongst other providers and it looks to be the best option for us, but this is potentially a showstopper, for now at least.

Any help/guidance would be much appreciated. Thanks in advance :-)

Steve.

Pragmasis Limited
https://SecurityForBikes.com

Ah ah! Update to this:

If I switch it to HTTPS on the Stripe webhook setup then it looks like it is fine. I had actually already set up the SSL certificate for our test domain so it was initially coming in to Stripe over HTTPS and then looking like it was trying to bounce back to HTTP on the response. Making it consistently HTTPS, not surprisingly, seems to work quite a bit better...

:-)

Apologies!

Pragmasis Limited
https://SecurityForBikes.com