Full immersion

The title of your post says "Full immersion" (suggesting that you exposed your phone to water), but an automated translation of the message (from Italian) is

"It doesn't work properly for me: I exclude the reception of calls for everyone except some, but I keep getting calls from everyone"

If you are talking about blocking unwanted phone calls, maybe there is something in the following Support articles that will help you to get the wanted behavior – or at least to understand why the system is behaving as it is now.

Block or avoid unwanted calls on iPhone - Apple Support

Detect and block spam phone calls - Apple Support

Block phone numbers, contacts, and emails on your iPhone or iPad - Apple Support

Please try contacting the Italian Apple Support page for help.

Prova a contattare la pagina di supporto Apple italiana per assistenza.

Contattaci - Supporto Apple ufficiale (IT)

If you can post in English, it might help us resolve the apparent mismatch between your post's title and its content. From the title, I also interpreted that as "went completely into a liquid."