Enter VAT number

Hi i am having a problem regarding when i enter a VAT number in the checkout. After the number is entered the tax is not zero it's still the same. I have enabled the option "Assume that VAT number is legit." in taxSettings.
I would like it to be zero if a customer enters a VAT number.

I am running version 3.9.

>I would like it to be zero if a customer enters a VAT number.
Do you use external plugin for changing TAX amount for customers with VAT ID?

Sorry, but i have noticed that it becomes zero if i do a reload on the checkout.
Is it possible to trigger a reload on the sum?

It would be nice if i don't need to do a reload on the whole page.

No i do not use a external plugin for changing TAX amount. It's nop core functionality that's used.

I am sorry that you wait for this answer.
I can't replicate this problem. If customer set VAT number plugin sends it to server and changed the order total...