This kind of issue seems to be caused by something other than our plugin.
The EU VAT Assistant takes all data directly from the order, when the payment process is completed. The VAT Validation occurs at the same time: if the VAT number is not matching the country, for whatever reason, then the order cannot be completed. If an order can be completed, then the country is correct. The EU VAT Assistant won’t look into past orders, that’s simply not how it works.
I’m afraid that I can’t say why the countries might be mismatching. There could be some conflict, caused by other plugins (disabling other plugins can help narrowing down the possible causes).
To determine the cause of the issue, we would have to conduct an investigation directly on your site, but we can’t do that as part of the free support provided via this forum. If you purchases a support plan, you can file a support request on our dedicated portal. If you don’t have one, you can contact us to request a consultation.
