I use PWA with only one language - German (but in Shopware I have two languages Eng and Ge). The problem with an error message from /checkout/cart/* endpoints are that they are only in English.
I tried to add the sw-language-id header, change the language of the sale channel, change snippets, and edit snippet sets but nothing worked. It looks like this part is hardcoded if it's true how can I solve this problem by myself?
I have an idea to create my plugin which will decorate /checkout/cart/* endpoints.