Invoice taxes, has a base -0.01 when tax percentage of 0,00000000%
An invoice has a tax percentage of 0,00000000 %.
When taxes are calculated for this invoice, the result is -0.01.
I noticed that in the _round_taxes() function within the TaxableMixin class, the value of rounded_amount is Decimal('0E-7'), and ultimately the value ends up being 0.01.
Converting it to float and then back to Decimal solved the problem.