Some IDR invoices with tax in the image are not recognising the tax from image

Some IDR invoices containing tax information in the image are not recognizing the tax details, even though we have selected the correct options in the ‘Manage Intelligent Document Recognition Options’ task. We have also trained the system through adaptive learning, but it still fails to identify the tax from the image. The customer is using a third-party tax solution, Vertex. Could someone help us understand why the system is behaving this way?