In most cases this is to do with the way Google pinpoints the geolocation of Zyte Smart Proxy Manager(formerly Crawlera) proxies. We try our best to match the location, but different websites sometimes detect the proxies to be from another country, as they use different geolocation databases.
If accurate geolocation is crucial for your use-case, upgrading to a Smart Proxy Manager Enterprise plan with residential IPs is the best option, because they prove to be much more reliable in this regard.
You may encounter pages in languages other than English while scraping Google with Smart Proxy Manager (even with a US-only account). To fix this, add Google custom search parameters to the requested URL, for instance: https://www.google.com/shopping/product/1847765387769146910?gl=us&hl=en&lr=lang_en. Here gl boosts search results for United States, hl sets the user interface language, and lr restricts the search to documents written in English. For more information please refer to https://developers.google.com/custom-search/v1/cse/list and https://developers.google.com/custom-search/docs/xml_results#WebSearch_Query_Parameter_Definitions.