iOS 26 Call Screening not working

I’m trying to use the new Call Screening feature in iOS 26 but it doesn’t activate. I’m in Mexico, my phone language is set to Spanish (Mexico), region is Mexico, Apple Intelligence is on, Siri is on and it's language is set to Spanish (Mexico), and I’ve enabled the call screening option that asks the caller to state a reason for the call.

When I receive calls from unknown numbers it just rings normally without screening. I’ve restarted the phone and checked settings several times.

Apple’s feature availability page says Call Screening is available in Mexico, so I’m not sure what I’m missing.