I have strange problem with VAT in Magento 2.4.3-p1. After migration from M1 I have empty VAT in checkout process. I have correct settings in 'Tax Rules' and 'Tax Zones and Rates'. My products have correct selected 'Tax class'. I have all settings in Configuration - Tax same as in old Magento1 instance. But in checkout I see VAT = 0.00. How can I debug it most easily and effective and find an error?
I debugged a method getStoreRate from \vendor\magento\module-tax\Model\Calculation.php and find that I lost rate tax for customers group. When I reset it from admin panel and rebuided an index I saw correct VAT value in checkout. That's all