False. There are mechanisms to undo PIX transactions. One such mechanism is the MED (official tool by the Central Bank). It can be used to help victims of scams, fraud and operating failures on the part of institutions so they can recover the cash).

https://www.bcb.gov.br/estabilidadefinanceira/pix-seguranca

There's also the different insurance plans offered by mostly all banks and payment-adjacent businesses.