Invalidrequest error using Amazon Pay multi currency

hi to all, i am facing problems with the amazon pay plugin. The amazon pay merchant is UK based but requires to receive payments in € EURO currency. By default amazon pay uk accepts only payments in sterling pund. so i installed the FOX – Currency Switcher Professional for WooCommerce plugin, set pound sterling as default currency and added € currency. no matter how many different types of configuration combinations i try, live amazon pay transaction results into “invalidrequest” error message.
Has anyone faced the same issues? has someone any idea how to fix this? though i set debugging in the amazon pay plugin, logs dont show any errors, as it seems that the amazon gateway api response is not captured. any help is warmly appreciated

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