Google bots regularly crawl the product pages’ structured data and compare with what were put in the feeds. This error message is an indication of mismatching data between the product page and the feed.
Google provides a tool to check the structured data of the product page.
The reason normally comes down to either one or both of mismatching price value and/or price currency.
Mismatching price value is normally because the price value was modified after the feed was generated, and not re-sync (or not re-sync soon enough) to Google.
If you are a paid user, you should not encounter this error because the app automatically re-sync any product updates to Google, including changes due to Shopify foreign currency rates changes for multi-currency shop.
With free package, the app only re-syncs product data regularly enough for the products not to expire in Google Merchant Center. The re-sync would typically be every 27 days.
If you are a paid user and see this error message, it is mostly because the shop is making multi-currency feeds using foreign currencies, and the product page is not configured properly to provide the right currency in its structured data. By default, most Shopify themes correctly switch currency on the product page user interface, but only show the store's default currency in structured data.
If you are familiar with Shopify theme editor, you can look for the code that provides structured data in the product template, something like this:
“priceCurrency”: “{{shop.currency}}”,
and change it to
“priceCurrency”: “{{ cart.currency.iso_code }}”
And that should be it.
If you are not comfortable doing it, contact your theme developer and ask him to fix it for you.
