How to find unpaid service invoices at a given date?

I’m wondering why I see only zero figures in this report, though I used the account_fr taxes and all my invoices show taxe amounts…

I’m not sure because the rule seems different for goods.

The doc tells:

When a payment lines is added to an invoice, the tax lines for the proportional amount are set on the corresponding tax code for the current period. If a payment line is removed from an invoice, the reverse operation is applied.

Is it possible to activate this module and have the already entered and paid invoices be correctly handled?