Tax amount of credit memo

Summary:

In test instance

draft invoice #3 was created with tax amount, later it was cancelled, draft invoice 5 but the tax amount is 0.00 instead of 6,255.06

The Draft invoice 4 was created similarly, there is a field User-Defined Fiscal Classification = AR NO TAX that allows to recalculate tax to zero :

but in the case of draft #3, we did not click on calculate Tax, and system derived the Tax amount 6,255.06 , that is why we attempt to Cancel it but we did not get the Tax amount derived.

Is there a way to recalculate the Tax amount ? but at the same time , it would need the User-Defined Fiscal Classification = null ? so it derives the original tax amount?