Encoding problem in PHP SoapClient and C# SOAP Server responses

Question

Hi, I have problems with special characters in soap responses.

All connections are made in utf-8 (in xml headers, SoapClient configuration, php source code, database connections, soap server responses) and I don't understand what is happening.

All special characters are replaced with a sharp "#" character.

For example: Instead of "Sólo alojamiento", the xml response returns "S#lo alojamiento"

I've tested the soap server using Wireshark and it returns utf-8. The "ó" char is encoded in hex as "C3B3". I don't understand what php is doing.

Do I need some type of conversion. Must I configure something in the SoapClient?

Thank you