Info Contacts UCM630X



I saw the new features “Contacts” of UCM 630x, referring to the screen that I am attaching, where as a test I associated with an external contact “3476663986” = “Ciccio1”, but if I call in input I see 3472283986 instead of “Ciccio1”, UCM does not associate the input number with the name?
Is it possible to do this?
How do you search for the contacts entered here?

n.b .: I’m starting to think that “Contacts” is for UCM internal use only, so I don’t see its usefulness