Tax amount in General Ledger Entry and Realized VAT Amount

Dear expert

I noticed that the Tax Amount in G/L Entry table and Tax Entry table matches (Based on exchange rate when invoice is posted). However they are different from Realized VAT Amount which is based on the exchange rate when payment is made.

May I know if the Tax Amount in G/L Entry table for the original invoice, the Amount in Tax Entry table, and the realized VAT Amount in Payment G/L Entries should always be the same?

Thank you

Kelsey