I developed a Magento2 webshop with a custom theme and some extensions. Now suddenly, the checkout page shows weird behavior.
When I go to /checkout I see the spinner indicating that the Magento is building the checkout page. But, then I only see the email field and the coupon box. All other steps and fields are there, but they are hidden by the steps js I think.
The Payment step is directly shown instead of the billing address step.
Does anyone know what's going on here?
You can find the store here: goo.gl/QLG3AS (Dutch)
The problem only seems to happen when (only) a configurable product is added to the cart, for example: goo.gl/gB30Bd. But if I add a simple product, for example: goo.gl/3vrCRX (alone, or with a configurable product) the checkout seem to work just fine.