The same way European EMIs sometimes call their services banking services, without actually being banks. In many places in the world, you can offer some bank-like services (such as accounts and cards) without being a bank. It doesn't make you a bank.
Where does it say EPB is listed︀ as a bank?
Here are the lists of banks:
Commercial banks: https://ocif.pr.gov/Consumidores/Lista Concesionarios/Bancos Comerciales.pdf
International banks: https://ocif.pr.gov/Consumidores/Lista Concesionarios/Entidades Bancarias Internacionales.pdf
I can only find EPB listed in the EFI list︁ you linked before. EFIs are not banks.
Where does it say EPB is listed︀ as a bank?
Here are the lists of banks:
Commercial banks: https://ocif.pr.gov/Consumidores/Lista Concesionarios/Bancos Comerciales.pdf
International banks: https://ocif.pr.gov/Consumidores/Lista Concesionarios/Entidades Bancarias Internacionales.pdf
I can only find EPB listed in the EFI list︁ you linked before. EFIs are not banks.