Bank Authentication

I really hope someone can help as I have spent the best part of 40 mins on chat to someone who has no idea.
our shop is a whoo commerce and linked to Keap.
When a customer purchases the product it asks for the payment to be authorised by the bank. But when they go to their bank app to accept the payment there is nothing there, the bank is not being notified. This is now happening on about 60% of our online orders.
I started by contacting Stripe, but they say its a Keap problem. Can anyone help please

Hi Heather, could you please tell us what type of Merchant Account you are using within Keap?

I recently had to change someone’s Merchant Account settings from Nexus Merchants to Keap native Stripe Integration. We have found out that Nexus Merchants is unable to support 3D Secure / Strong Customer Authentication (SCA). We are hoping that the native Stripe Integration is fully working with SCA here.

We have also noticed the same thing with support. If you raise the issue with Keap they say it is Stripe. If you speak to Stripe they say that the vendor needs to be using the Payment Intents API. You just go around in circles.