A client is using the CustomerGroupPrices to set up a more complex pricing strategy, and that works just fine… until you get to the checkout. On the first page where you enter your shipping options it shows the correct price: https://imgur.com/S3Dtl6U, but once you continue to payment it shows the incorrect price: https://i.imgur.com/3rmIDtb.png. But once you refresh the page it shows the right price.
I am very new to magento and could really use some help at how to fix this. I already figured out that the call to /rest/de/V1/carts/mine/shipping-information is where this incorrect data comes from, but I can’t figure out where this call is handled. Any pointers would be greatly appreciated.