I am not sure about how Google might treat an Italian site, however, I rather suspect the process is the same. So I will continue.
In your case, Google likely does not like the title as provided in the title tag. It is important that the title tag is not too short or too long and that the title tag be carefully crafted especially when using the pipe character. There may be other conditions under which Google will not use the title as given as a SERP link.
In your case, Google is likely looking to traditional pages and traditional links. Certain pages have special importance; About, Contact, Company Info, Privacy Policy, and so on, that have been treated somewhat differently in the original parser models where pages were read top-to-bottom like any page in a book. These pages were different in that there were expectations put upon them by users. Contact, for example, would have contact information and special agents (as in the AI tradition) were used to extract contact information. Perhaps part of what you are experiencing is related to this. Who knows for sure?
What we can say is this. If you craft your title tag for length, you should be fine. Here are some answers I have given in the past that may help you to understand what is going on.
Speaks to how Google can change SERP links.
Title tag different from title appearing in Google?
Speaks to the title length.
My title tag doesn't appear to be getting crawled by Google properly
Speaks to the title length.
Title in Google does not match <title> of document