There are several similar questions, but all those I found are pointing to old versions of Odoo and are not helpful.

So I have several invoices that Odoo considers to be "partially paid" just because it's looking at the amount I got before the transaction fees, instead of the amount the User actually paid. This already makes no sense but whatever.

If I click Pay and manually add a payment, even after clicking Validate on the payment, exactly nothing at all happens, the invoice still claims that there is an amount due precisely as if I did nothing.

What am I supposed to do?