Google Merchant bot crawls the wrong currency

We recently changed our old multicurrency plugin for your Curcy: Woocommerce Multi Currency. We are using Nitropack for caching our site. We run google shopping ads. Our base currency is EUR, and we use also USD, CAD, GBP and AUD and since we use this plugin we receive continuously the same google merchant error about price mismatch. This happens in some products randomly. Not in all products. The prices in our feed is correct but the google bot wrongly crawls the price in our site. The bot always takes the base currency (EUR) instead the correct one forced in the url with the suffix (?wmc-currency=USD, for example)

From our side it seems the site is working correctly and assigns correctly the currency depending of the country.
Can you help me to solve this issue?

Regards.