Hello,
Thank you for reaching out to us, we are here to help.
The language that is being used for the buttons is decided by PayPal on their server. Our plugin gathers the customer details on the website and sends them to the PayPal server (such as IP, OS, language settings, etc). The PayPal server then reviews these details and decides what the customer should be seeing. The outcome can be different for every device, user or browser, so you might want to try this on another device and see if you still get the same outcome.
Currently, there is no option to override this situation and force 1 language for these buttons, but we do have a feature request open to get this introduced. You can find some details on this GitHub issue, that we are working on for this purpose.
I will link this thread to our internal feature request for keeping you up-to-date if the thread allows us to still update it once the feature has been release.
Please let me know if you have any more questions regarding this situation.
Kind regards,
Joost
